1 Sys_Parameters Help is provided for the system parameters listed below. 2 ACP_BASEPRIO ACP_BASEPRIO sets the base priority for all ACPs. The DCL command SET PROCESS/PRIORITY can be used to reset the base priorities of individual ACPs. ACP_BASEPRIO is not applicable for XQPs. ACP_BASEPRIO is a DYNAMIC parameter. 2 ACP_DATACHECK ACP_DATACHECK controls the consistency checks that are performed on internal file system metadata such as file headers. ACP_DATACHECK is a bit mask. The following table shows the bits that are defined currently: Bit Description 0 Set this bit to perform consistency checks on read operations. When this bit is set, the IO$M_DATACHECK function modifier is automatically set on all subsequent IO$_ READLBLK operations that read file system metadata (see the OpenVMS I/O User's Reference Manual). 1 Set this bit to perform consistency checks on write operations. When this bit is set, the IO$M_DATACHECK function modifier is automatically set on all subsequent IO$_ WRITELBLK operations that read file system metadata (see the OpenVMS I/O User's Reference Manual). 2 Set this bit to perform read-after-write consistency checks. This is similar to setting bit 1, except that in this case the file system does the checks, not the lower level device or disk driver. Note that read-after-write consistency checks are not allowed on deferred writes. Deferred writes are turned off if this bit is set. 3 Reserved for Compaq use only; must be zero. 4 Reserved for Compaq use only; must be zero. 5 and 6 These two bits control the checks that are performed on reads and writes of directory blocks. You can select one of four different levels: By Select Setting This Bit 6 And Bit 5 To Check That... Level... to... to... The block is a valid 0 0 0 directory block (reads only) The block is a valid 1 0 1 directory block (reads and writes) The block is a valid 2 1 0 directory block and contains valid entries (reads and writes) The block is a valid 3 1 1 directory block and contains valid entries in correct alphanumeric order (reads and writes) When you set the SYSTEM_CHECK system parameter to 1, you enable level 3 checking of directory blocks. Write errors result in BUGCHECK and crash your system; read errors exit with error status SS$_BADDIRECTORY. 7 Reserved for Compaq use only; must be zero. 2 ACP_DINDXCACHE ACP_DINDXCACHE controls the size of the directory index cache and the number of buffers used on a cachewide basis. Also, ACP_DINDXCACHE builds a temporary index into the directory file, thereby reducing search time and directory header lookup operations. ACP_DINDXCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_DIRCACHE ACP_DIRCACHE sets the number of pages for caching directory blocks. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the directory data block cache. ACP_DIRCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_EXTCACHE ACP_EXTCACHE sets the number of entries in the extent cache. Each entry points to one contiguous area of free space on disk. A specification of 0 means no cache. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the extent cache. ACP_EXTCACHE is a DYNAMIC and FEEDBACK parameter. 2 ACP_EXTLIMIT ACP_EXTLIMIT specifies the maximum amount of free space to which the extent cache can point, expressed in thousandths of the currently available free blocks on the disk. For example, if available free space on the disk is 20,000 blocks, a specification of 10 limits the extent cache to 200 blocks. The computed, installed value is usually adequate. Users with four or more OpenVMS Cluster node systems might want to adjust this parameter. ACP_EXTLIMIT is a DYNAMIC parameter. 2 ACP_FIDCACHE ACP_FIDCACHE sets the number of file identification slots cached. A specification of 1 means no cache. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the FID caches. ACP_FIDCACHE is a DYNAMIC and FEEDBACK parameter. 2 ACP_HDRCACHE ACP_HDRCACHE sets the number of pages for caching file header blocks. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the file header caches. ACP_HDRCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_MAPCACHE ACP_MAPCACHE sets the number of pages for caching index file bitmap blocks. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the bitmap cache. ACP_MAPCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_MAXREAD ACP_MAXREAD sets the maximum number of directory blocks read in one I/O operation. ACP_MAXREAD is a DYNAMIC parameter. 2 ACP_MULTIPLE ACP_MULTIPLE enables (1) or disables (0) the default creation of a separate disk XQP cache for each volume mounted on a different device type. Prior to Version 4.0, a separate ACP process was created for each device type if this parameter was enabled. Because ACP operations are now handled by the per process XQP, such separate processes are no longer created. In general, having multiple caches is unnecessary. One large cache is more efficient than several small ones. ACP_MULTIPLE can be overridden on an individual-volume basis with the DCL command MOUNT. ACP_MULTIPLE is an AUTOGEN and DYNAMIC parameter. 2 ACP_QUOCACHE ACP_QUOCACHE sets the number of quota file entries cached. A specification of 0 means no cache. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the quota caches. ACP_QUOCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_REBLDSYSD ACP_REBLDSYSD specifies whether the system disk should be rebuilt if it was improperly dismounted with extent caching, file number caching, or disk quota caching enabled. The ACP_REBLDSYSD default value (1) ensures that the system disk is rebuilt. Setting the value to 0 means the disk is not rebuilt. Depending on the amount of caching enabled on the volume before it was dismounted, the rebuild operation may consume a considerable amount of time. Setting the value of ACP_REBLDSYSD to 0 specifies that the disk should be returned to active service immediately. If you set ACP_REBLDSYSD to 0, you can enter the DCL command SET VOLUME/REBUILD at any time to rebuild the disk. 2 ACP_SHARE ACP_SHARE enables (0) or disables (1) the creation of a global section for the first ACP used, enabling succeeding ACPs to share its code. This parameter should be set to 0 when ACP_MULTIPLE is on. ACP_SHARE is a DYNAMIC parameter. 2 ACP_SWAPFLGS ACP_SWAPFLGS enables or disables swap through the value of a 4-bit number for the following four classes of ACPs: Bit Class of ACP 0 Disks mounted by MOUNT/SYSTEM 1 Disks mounted by MOUNT/GROUP 2 Private disks 3 Magnetic tape ACP If the value of the bit is 1, the corresponding class of ACPs can be swapped. The value of decimal 15 (hexadecimal F-all bits on) enables swap for all classes of ACP. A value of decimal 14 disables swap for ACPs for volumes mounted with the /SYSTEM qualifier but leaves swap enabled for all other ACPs. Note that one has only disk ACPs present if they are specifically requested at mount time or if a Files-11 On-Disk Structure Level 1 disk is mounted. In general, only bit 3 is significant because usually no file ACPs exist. ACP_SWAPFLGS is an AUTOGEN and DYNAMIC parameter. 2 ACP_SYSACC ACP_SYSACC sets the number of directory file control blocks (FCBs) that are cached for disks mounted with the /SYSTEM qualifier. Each directory FCB contains a 16-byte array containing the first letter of the last entry in each block of the directory (or group of blocks if the directory exceeds 16 blocks). Since entries in a directory are alphabetical, the cached FCB provides quick access to a required directory block. This parameter value should be roughly equivalent to the number of directories that are in use concurrently on each system volume. It might be overridden on a per-volume basis with the /ACCESSED qualifier to the DCL command MOUNT. The value should be kept low in systems with small physical memory and little file activity, because the FCBs require a significant amount of space in the nonpaged dynamic pool. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the FCB caches. ACP_SYSACC is an AUTOGEN and DYNAMIC parameter. 2 ACP_WINDOW ACP_WINDOW sets the default number of window pointers to be allocated in a window for a default file access, for disks mounted with the /SYSTEM qualifier. ACP_WINDOW is a DYNAMIC parameter. 2 ACP_WORKSET ACP_WORKSET sets the default size of a working set for an ACP. A specification of 0 permits the ACP to calculate the size. This value should be nonzero only on small systems where memory is tight. Too small a value causes excessive ACP page, while too large a value causes excessive physical memory to be consumed by the ACP. Note that this parameter has no effect on the per- process XQP. ACP_WORKSET is a DYNAMIC parameter. 2 ACP_WRITEBACK ACP_WRITEBACK enables writeback caching. The default value of ACP_WRITEBACK is 1, which enables writeback caching. To disable writeback caching, set ACP_WRITEBACK to 0. On ODS-2 disks, only PATHWORKS servers can use writeback caching. All other applications use writethrough caching. ACP_WRITEBACK is a DYNAMIC parameter. 2 ACP_XQP_RES ACP_XQP_RES controls whether the XQP is currently in memory. The default value (1) specifies that the XQP is permanently in memory. Change the default only on restricted memory systems with a small number of users and little or no file activity that requires XQP intervention. Such activity includes file opens, closes, directory lookups, and window turns. 2 AFFINITY_SKIP AFFINITY_SKIP controls the breaking of implicit affinity. The value indicates the number of times a process is skipped before being moved. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 AFFINITY_TIME AFFINITY_TIME controls the breaking of implicit affinity. The value indicates how long a process remains on the compute queue. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 ALLOCLASS ALLOCLASS determines the device allocation class for the system. The device allocation class is used to derive a common lock resource name for multiple access paths to the same device. 2 ARB_SUPPORT (Alpha only) The Access Rights Block (ARB) compatibility option, the ARB_SUPPORT system parameter, is provided specifically to support products that have not yet been updated with the new per-thread security Persona Security Block (PSB) data structure. Changing the value of ARB_SUPPORT from 2 or 3 (the default) to any other value can affect the operation of these products. NOTE Compaq recommends that all Version 7.3 systems have the ARB_SUPPORT parameter set to 3 (the default). Do not change the ARB_SUPPORT parameter to any other value until all products dependent on the ARB and associated structures have been modified for the new environment. The following table describes ARB_SUPPORT parameters. ARB_SUPPORT Parameter Value Behavior ISS$C_ARB_ 0 The obsolete kernel data cells are not NONE maintained by the system. Fields are initialized to zero (or set to invalid pointers) at process creation. ISS$C_ARB_ 1 The obsolete kernel data cells are CLEAR cleared (or set to invalid pointers) when the code would have set up values for backward compatibility. ISS$C_ARB_ 2 The obsolete cells are updated with READ_ONLY corresponding security information stored in the current PSB when a $PERSONA_ASSUME is issued. ISS$C_ARB_ 3 (de- Data is moved from the obsolete cells to FULL fault) the currently active PSB on any security- based operation. ARB_SUPPORT is a DYNAMIC parameter. 2 AUTO_DLIGHT_SAV AUTO_DLIGHT_SAV is set to either 1 or 0. The default is 0. If AUTO_DLIGHT_SAV is set to 1, OpenVMS automatically makes the change to and from daylight saving time. 2 AWSMIN On VAX systems, AWSMIN establishes the lowest number of pages to which a working set limit can be decreased by automatic working set adjustment. On Alpha systems, AWSMIN establishes the lowest number of pagelets to which a working set limit can be decreased by automatic working set adjustment. AWSMIN is a DYNAMIC parameter. 2 AWSTIME AWSTIME specifies the minimum amount of processor time that must elapse for the system to collect a significant sample of a working set's page fault rate. The time is expressed in units of 10 milliseconds. The default value of 20, for example, is 200 milliseconds. Some application configurations that have a large number of memory-intensive processes may benefit if the value is reduced. The value can be as low as 4. AWSTIME expiration is checked only at quantum end. Reducing its value and not reducing QUANTUM effectively sets the value of AWSTIME equal to the value of QUANTUM. AWSTIME is a DYNAMIC parameter. 2 BALSETCNT BALSETCNT sets the number of balance set slots in the system page table. Each memory-resident working set requires one balance set slot. You can monitor the active system with the DCL command SHOW MEMORY or the MONITOR PROCESSES command of the Monitor utility to determine the actual maximum number of working sets in memory. If this number is significantly lower than the value of BALSETCNT, this parameter value may be lowered. If all balance set slots are being used, raise the value of BALSETCNT. Never set BALSETCNT to a value higher than 2 less than MAXPROCESSCNT. If physical memory is a significant system constraint, consider lowering this value even further. However, if your system runs with a number of processes nearly equal to MAXPROCESSCNT, lowering BALSETCNT will force swapping to occur, which can affect system performance. Note that virtual balance slots (VBS) can affect the values of BALSETCNT and MAXPROCESSCNT. BALSETCNT is an AUTOGEN, GEN, and MAJOR parameter. 2 BORROWLIM BORROWLIM defines the minimum number of pages required on the free-page list before the system permits process growth beyond the working set quota (WSQUOTA) for the process. This parameter should always be greater than FREELIM. This parameter allows a process to grow beyond the value set by the working set quota (WSQUOTA) to the working set quota extent (WSEXTENT) on a system that has a substantial memory on the free- page list. This automatic working set adjustment also depends upon the values of parameters WSINC, PFRATH, and AWSTIME. Working set growth attempts to alleviate heavy page faulting. To make use of this growth, you must also set the user's WSEXTENT authorization quota to a larger number than the WSQUOTA value. BORROWLIM is an AUTOGEN, DYNAMIC and MAJOR parameter. 2 BREAKPOINTS If XDELTA is loaded, BREAKPOINTS enables additional built-in calls for XDELTA during the boot sequence. The breakpoints that are enabled may change from release to release of OpenVMS. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 BUGCHECKFATAL BUGCHECKFATAL enables or disables the conversion of nonfatal bugchecks into fatal bugchecks. The system must be rebooted on a fatal bugcheck. A nonfatal bugcheck places an entry only in the error log and deletes the corresponding process. This parameter should normally be OFF (0); you should set it ON (1) only when the executive is being debugged. Setting the SYSTEM_CHECK parameter to 1 has the effect of setting BUGCHECKFATAL to ON (1). BUGCHECKFATAL is a DYNAMIC parameter. 2 BUGREBOOT BUGREBOOT enables or disables automatic rebooting of the system if a fatal bugcheck occurs. This parameter should normally be on (1); set it off (0) only when the executive is being debugged. BUGREBOOT is a DYNAMIC parameter. 2 CHANNELCNT CHANNELCNT specifies the number of permanent I/O channels available to the system. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 CHECK_CLUSTER (VAX only) CHECK_CLUSTER is the VAXCLUSTER parameter sanity check. When CHECK_CLUSTER is set to 1, SYSBOOT outputs a warning message and forces a conversational boot if it detects that the VAXCLUSTER parameter is set to 0. 2 CLASS_PROT CLASS_PROT performs the nondiscretionary classification checks. CLASS_PROT is also checked by XQP to determine if a classification block should be added to the header of any created files. CLASS_PROT is a DYNAMIC parameter. 2 CLISYMTBL CLISYMTBL sets the size of the command interpreter symbol table, which controls the number of DCL or MCR symbols that can be created. CLISYMTBL is a DYNAMIC parameter. 2 CLOCK_INTERVAL (VAX only) CLOCK_INTERVAL sets the number of microseconds between the hardware interval timer clock interrupts. It has no effect on processors that have implemented only the subset interval clock registers. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 CLUSTER_CREDITS CLUSTER_CREDITS specifies the number of per-connection buffers a node allocates to receiving VMS$VAXcluster communications. If the SHOW CLUSTER command displays a high number of credit waits for the VMS$VAXcluster connection, you might consider increasing the value of CLUSTER_CREDITS on the other node. However, in large cluster configurations, setting this value unnecessarily high consumes a large quantity of nonpaged pool. Each receive buffer is at least SCSMAXMSG bytes in size but might be substantially larger depending on the underlying transport. It is not required for all nodes in the cluster to have the same value for CLUSTER_CREDITS. For small or memory-constrained systems, the default value of CLUSTER_CREDITS should be adequate. 2 CONCEAL_DEVICES CONCEAL_DEVICES enables or disables the use of concealed devices. By default, this parameter is set to enable concealed devices (1). This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 CRD_CONTROL This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. On VAX systems, CRD_CONTROL serves the function of CRDENABLE in earlier releases. On Alpha systems, CRD_CONTROL can be used to expand the function defined by CRDENABLE. CRD_CONTROL is a bit mask for corrected read data (CRD) soft error control flags. These flags control the use of CRDERROR routines. On VAX systems, the following bits are defined: Bit Description 0 Enables CRD processing for all systems. 1 Enables scrubbing (rewriting) of the memory location that induced the CRD. 2 Enables page replacement of the pages that exhibit repeated CRD errors. 3 Forces all memory pages to be included in the PFN database. On systems that contain more than 512 megabytes of memory, all memory is mapped by the PFN database by default. This bit allows the mapping to occur on systems with less than 512 megabytes of memory. Default values are different for VAX and Alpha systems. On VAX systems, the default is 7, which enables CRD processing, scrubbing, and page replacement. On Alpha systems, the following bits are defined: Bit Description 0 Enables CRD processing for all systems. 1 Enables scrubbing (rewriting) of the memory location that induced the CRD. 2 Enables page replacement of the pages that exhibit repeated CRD errors. 3 Forces all memory pages to be included in the PFN database. On systems that contain more than 512 megabytes of memory, all memory is mapped by the PFN database by default. This bit allows the mapping to occur on systems with less than 512 megabytes of memory. 4 Enables extended CRD handling, if available. 5 Enables loading of driver and process for handling server management events. Platform-specific code usually sets this bit if the required hardware and firmware support are available. 24-31 Reserved for platform-specific error-handling control. On Alpha systems, the default setting is 22, which enables CRD processing, scrubbing, page replacement, and extended CRD handling. 2 CRDENABLE (Alpha only) CRDENABLE enables or disables detection and logging of memory-corrected read data (ECC) errors. This parameter should normally be set to (1). Beginning with OpenVMS Version 7.2, CRD_CONTROL can expand the function of CRDENABLE. (Refer to CRD_CONTROL.) 2 CTLIMGLIM CTLIMGLIM specifies the size of the default image I/O segment; that is channel table and initial buffer pool for image-related file and RMS I/O. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 CTLPAGES CTLPAGES specifies the size of P1 pool. CTLPAGES is automatically changed only when the process logical name table, DCL symbols, or some layered products require an increase in the size of the P1 pool area. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. CTLPAGES is an AUTOGEN parameter. 2 CWCREPRC_ENABLE CWCREPRC_ENABLE controls whether an unprivileged user can create a process on another OpenVMS Cluster node. The default value of 1 allows an unprivileged user to create a detached process with the same UIC on another node. A value of 0 requires that a user have DETACH or CMKRNL privilege to create a process on another node. 2 DBGTK_SCRATCH (Alpha only) DBGTK_SCRATCH specifies how many pages of memory are allocated for the remote debugger. This memory is allocated only if remote debugging is enabled with the 8000 boot flag. Normally, the default value is adequate, but if the remote debugger issues an error message, you should increase this value. See Writing OpenVMS Alpha Device Drivers in C for more information. (This manual has been archived but is available on the OpenVMS Documentation CD-ROM.) 2 DEADLOCK_WAIT DEADLOCK_WAIT defines the number of seconds that a lock request must wait before the system initiates a deadlock search on behalf of that lock. Setting DEADLOCK_WAIT to 0 disables deadlock checking. Setting DEADLOCK_WAIT to a value greater than 0 but still less than the default setting provides faster detection of deadlocks but requires more CPU usage. DEADLOCK_WAIT is a DYNAMIC parameter. 2 DEFMBXBUFQUO DEFMBXBUFQUO sets the default for the mailbox buffer quota size in bytes when this value is not specified in a Create Mailbox ($CREMBX) system service call. DEFMBXBUFQUO is a DYNAMIC parameter. 2 DEFMBXMXMSG DEFMBXMXMSG sets the default for the mailbox maximum message size in bytes when this value is not specified in a Create Mailbox ($CREMBX) system service call. DEFMBXMXMSG is a DYNAMIC parameter. 2 DEFPRI DEFPRI sets the base default priority for processes. DEFPRI is a DYNAMIC parameter. 2 DEFQUEPRI DEFQUEPRI establishes the scheduling priority for jobs entered in batch and output (printer, server, and terminal) queues when no explicit scheduling priority is specified by the submitter. The value of this parameter can range from 0 to 255; the default value is 100. The value of DEFQUEPRI should be less than or equal to MAXQUEPRI. NOTE DEFQUEPRI refers to relative queue scheduling priority, not the execution priority of the job. DEFQUEPRI is a DYNAMIC parameter. 2 DEVICE_NAMING (Alpha only) DEVICE_NAMING is a bit mask indicating whether port allocation classes are used in forming SCSI device names. Following is the bit definition: Bit Definition 0 If 1, enable new naming. 1 Must be 0. This bit is reserved for use by Compaq. For more information about port allocation classes, see OpenVMS Cluster Systems. 2 DISABLE_UPCALLS DISABLE_UPCALLS is primarily a debugging aid. It allows the system manager to disable threads upcalls of specific types for the entire system. The value is a bit mask, with the bits corresponding to the upcall types. The upcall types are defined in the definition macro $TMCDEF. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. DISABLE_UPCALLS is a DYNAMIC parameter. 2 DISK_QUORUM The DISK_QUORUM parameter is the name of an optional quorum disk in ASCII. ASCII spaces indicate that no quorum disk is being used. DISK_QUORUM is a DYNAMIC parameter. 2 DLCKEXTRASTK (VAX only) DLCKEXTRASTK specifies the amount of extra interrupt stack (in bytes) to leave when doing a deadlock search. This parameter is not used on Alpha systems. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 DNVOSI1 DNVOSI1 is reserved to DECnet-Plus for OpenVMS. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 DORMANTWAIT DORMANTWAIT specifies, in seconds, the amount of time that can elapse without a significant event before the system treats a low-priority computable process as a DORMANT process for scheduling purposes. (A low-priority process is a non real-time process whose current priority is equal to or less than the value specified by the system parameter DEFPRI [default=4].) After SUSP (suspended) processes, DORMANT processes are the most likely candidates for memory reclamation by the swapper. Increasing the value of DORMANTWAIT can increase the interval that a low priority process blocks a high priority process if that low priority process is holding a lock or resource that the higher priority process is waiting for. DORMANTWAIT is a DYNAMIC parameter. 2 DR_UNIT_BASE (Alpha only) DR_UNIT_BASE specifies the base value from which unit numbers for DR devices (DIGITAL StorageWorks RAID Array 200 Family logical RAID drives) are counted. DR_UNIT_BASE provides a way for unique RAID device numbers to be generated. DR devices are numbered starting with the value of DR_UNIT_BASE and then counting from there. For example, setting DR_UNIT_BASE to 10 produces device names such as $1$DRA10, $1$DRA11, and so on. Setting DR_UNIT_BASE to appropriate, nonoverlapping values on all cluster members that share the same (nonzero) allocation class ensures that no two RAID devices are given the same name. DR_UNIT_BASE is a GEN parameter. 2 DUMPBUG DUMPBUG enables (1) or disables (0) the writing of error log buffers and memory contents to SYS$SYSTEM:SYSDUMP.DMP when a fatal bugcheck occurs. This parameter should be off (0) only when the executive is being debugged. 2 DUMPSTYLE DUMPSTYLE specifies the method of writing system dumps. DUMPSTYLE is a 32-bit mask, with the following bits defined. Each bit can be set independently. The value of the system parameter is the sum of the values of the bits that have been set. Remaining or undefined values are reserved for Compaq use only. Bit Mask Description 0 00000001 0 = Full dump (SYSGEN default). The entire contents of physical memory are written to the dump file. 1 = Selective dump. The contents of memory are written to the dump file selectively to maximize the usefulness of the dump file while conserving disk space. 1 00000002 0 = Minimal console output. 1 = Full console output (includes stack dump, register contents, and so on). 2 00000004 0 = Dump to system disk. 1 = Dump off system disk (DOSD) to an alternate disk. (Refer to the OpenVMS System Manager's Manual for details.) 3 (Alpha only) 00000008 0 = Do not compress. 1 = Compress. (See note below.) 4 - 14 Reserved for Compaq use only. 15 (VAX only) 00008000 0 = Disable use of bits 16 - 27. 1 = Enable use of bits 16 - 27. 16 - 27 (VAX 0FFF0000 Range of DOSD unit numbers. only) 28 - 31 Reserved for Compaq use only. Note that VAX systems do not support dump compression. Also, VAX-only bits are specific to VAX 7000s. If you plan to enable the Volume Shadowing minimerge feature on an Alpha system disk, be sure to specify DOSD to an alternate disk. NOTE On Alpha systems, you can save space on the system disk and, in the event of a crash, save time recording the system memory, by using the OpenVMS Alpha dump compression feature. Unless you override the default AUTOGEN calculations (by setting DUMPSTYLE in MODPARAMS.DAT), AUTOGEN uses the following algorithm: o On a system with less than 128 MB of memory, the system sets the DUMPSTYLE to 1 (a raw selective dump) and sizes the dump file appropriately. o On a system with 128 MB of memory or greater, the system sets the DUMPSTYLE to 9 (a compressed selective dump), and creates the dump file at two-thirds the value of the corresponding raw dump. Examples: The mask of 00000006 directs the system to send a full dump, with full console output, off the system disk (to the alternate disk). For a VAX 7000, a mask of 00098006 directs the system to send a full dump with full console output to the DOSD whose unit number is 9. On Alpha systems, the mask of 00000009 directs the system to compress a selective dump with minimal console output. DUMPSTYLE has AUTOGEN and DYNAMIC attributes. 2 ERLBUFFERPAGES ERLBUFFERPAGES specifies the amount of memory to allocate for each buffer requested by the ERRORLOGBUFFERS parameter. On VAX systems, ERLBUFFERPAGES has a default value of 2 pages and a maximum value of 32 pages. On Alpha systems, ERLBUFFERPAGES has a default value of 4 pagelets and a maximum value of 32 pagelets. On Alpha systems, ERLBUFFERPAGES is an AUTOGEN-altered parameter. 2 ERRORLOGBUFFERS ERRORLOGBUFFERS specifies the number of buffers reserved for system error log entries. Each buffer is ERLBUFFERPAGES in length. If ERRORLOGBUFFERS is too low, messages might not be written to the error log file. If it is too high, unneeded physical pages can be consumed by the error log buffers. If you increase ERRORLOGBUFFERS, you must also increase the size of the system dump file. 2 EXPECTED_VOTES EXPECTED_VOTES specifies the maximum number of votes that may be present in a cluster at any given time. Set it to a value that is equal to the sum of the vote parameters of all cluster members, plus any votes that are contributed by the quorum disk. This value is used to automatically derive the number of votes that must be present for the cluster to function (quorum). EXPECTED_VOTES is an AUTOGEN attribute parameter. 2 EXTRACPU EXTRACPU sets the time, in units of 10 milliseconds, allotted to each of a process's exit handlers (for each access mode) after the process times out (that is, reaches its CPU time limit). EXTRACPU is a DYNAMIC attribute parameter. 2 EXUSRSTK EXUSRSTK specifies the amount of space provided by the image activator to recover from a stack overflow error. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 FAST_PATH (Alpha only) FAST_PATH is a static system parameter that enables (1) or disables (0) the Fast Path performance features for all Fast Path-capable ports. Starting in OpenVMS Version 7.2, FAST_PATH is enabled by default. In Versions 7.0 and 7.1, FAST_PATH was disabled by default. For additional information, see FAST_PATH_PORTS and IO_PREFER_ CPUS. 2 FAST_PATH_PORTS (Alpha only) FAST_PATH_PORTS is a static parameter that deactivates Fast Path for specific drivers. FAST_PATH_PORTS is a 32-bit mask. If the value of a bit in the mask is 1, Fast Path is disabled for the driver corresponding to that bit. A value of -1 specifies that Fast Path is disabled for all drivers that the FAST_PATH_PORTS parameter controls. Bit position zero controls Fast Path for PKQDRIVER (for parallel SCSI), and bit position one controls Fast Path for FGEDRIVER (for Fibre Channel). Currently, the default setting for FAST_ PATH_PORTS is 0, which means that Fast Path is enabled for both PKQDRIVER and FGEDRIVER. In addition, note the following: o CI drivers are not controlled by FAST_PATH_PORTS. Fast Path for CI is enabled and disabled exclusively by the FAST_PATH system parameter. o FAST_PATH_PORTS is relevant only if the FAST_PATH system parameter is enabled (equal to 1). Setting FAST_PATH to zero has the same effect as setting FAST_PATH_PORTS to -1. For additional information, see FAST_PATH and IO_PREFER_CPUS. 2 FREEGOAL FREEGOAL establishes the number of pages that you want to reestablish on the free-page list following a system memory shortage. Memory shortages occur when the system drops below the minimum number of pages required on the free-page list (FREELIM). The value of FREEGOAL must always be greater than or equal to the value of FREELIM. FREEGOAL has the AUTOGEN, DYNAMIC, and MAJOR attributes. 2 FREELIM FREELIM sets the minimum number of pages that must be on the free-page list. The system writes pages from the modified-page list, swaps out working sets, or reduces the size of the working sets to maintain the minimum count. While the larger free-page list generally means less page I/O, it also means less space for the balance set, which tends to result in more swap I/O. You can monitor the size of the free-page list, the amount of page, and the amount of swap with the MONITOR IO command of the Monitor utility. FREELIM has the AUTOGEN and MAJOR attributes. 2 GALAXY (Alpha Galaxy platforms only) The GALAXY parameter controls whether the specified instance participates in a Galaxy sharing set. Specify one of the following: Value Description 0 Never load. Do not participate in a Galaxy sharing set. 1 Always load. Participate in a Galaxy sharing set. The default value is 0. GALAXY is not an AUTOGEN parameter. 2 GBLPAGES GBLPAGES sets the number of global page table entries allocated at bootstrap time. Each global section requires 1 global page table entry per section page, plus 2 entries, with the total rounded up to an even number. Users with CMKRNL privilege can change this parameter on a running system. Increasing the value of this parameter allows the global page table to expand, on demand, up to the maximum size. The default value is sufficient for the images normally installed as shared in the system startup command procedures. Once the system is running and all global sections are created, you can examine the actual requirements with the /GLOBAL qualifier of the Install utility (INSTALL) and reduce the value of GBLPAGES accordingly. However, do not set the value of this parameter too low, because the page table entries use little permanently resident memory. If you plan to install many user images as shared, or if user programs are likely to create many global sections, you must increase the value of this parameter. GBLPAGES has the AUTOGEN, DYNAMIC, FEEDBACK, GEN, and MAJOR attributes. 2 GBLPAGFIL GBLPAGFIL defines the maximum number of systemwide pages allowed for global page-file sections (scratch global sections that can be used without being mapped to a file). These global page- file sections can be temporary, permanent, system, or group, and are allocated from the page file specified in the system process header at bootstrap time. When you allow pages for global page-file sections, you must increase the size of the page file accordingly. Users with CMKRNL privilege can change this parameter value on a running system. Global page-file sections are created with the Create and Map Section system services ($CREATE_GPFILE, $CRMPSC, and $CRMPSC_ GPFILE_64) without an explicit disk file. These sections are used for the RMS global buffers required for shared files. Users of shared files should note that global page-file sections cause both the global page table and the default system page file (PAGEFILE.SYS) to be used. If the value of GBLPAGFIL is too small, $CRMPSC issues an error message when you attempt to create global page-file sections. You must have scratch global sections if you use RMS global buffers. Each file using global buffers requires, in the system page file, the file's bucket size multiplied by the number of global buffers for that file. If the file's bucket size varies, as with RMS indexed files, use the maximum bucket size. For shared sequential files, use the multiblock count of the first stream to perform the $CONNECT service in place of the file's bucket size. The default value for this parameter is adequate for most systems. However, if your site uses RMS global buffering to a significant extent, you may need to raise the value of GBLPAGFIL. Use the /GLOBAL qualifier of the Install utility to examine the number of pages consumed by RMS global buffers. The global sections used by RMS for global buffers have the prefix RMS$ followed by 8 hexadecimal digits. Global buffers are enabled with the DCL command SET FILE/GLOBAL_BUFFERS, which is described in the OpenVMS DCL Dictionary. GBLPAGFIL is an AUTOGEN-altered and a DYNAMIC parameter. 2 GBLSECTIONS GBLSECTIONS sets the number of global section descriptors allocated in the system header at bootstrap time. Each global section requires one descriptor. Each descriptor takes 32 bytes of permanently resident memory. The default value is sufficient for the images normally installed as shared in the system startup command procedures. Once the system is running and all global sections are created, you can examine the actual requirements with the /GLOBAL qualifier of the Install utility and reduce the value of GBLSECTIONS accordingly. However, the value of this parameter should not be set too low. If you plan to install many user images as shared, or if user programs are likely to create many global sections, you must increase the value of this parameter. If the value of GBLSECTIONS is too small, you receive a message from the Install utility at system startup time or whenever you install images manually. Note that too large a value for GBLSECTIONS wastes physical memory. GBLSECTIONS has the AUTOGEN, FEEDBACK, GEN, and MAJOR attributes. 2 GH_EXEC_CODE (Alpha only) GH_EXEC_CODE specifies the size in pages of the execlet code granularity hint region. GH_EXEC_CODE has the AUTOGEN and FEEDBACK attributes. 2 GH_EXEC_DATA (Alpha only) GH_EXEC_DATA specifies the size in pages of the execlet data granularity hint region. GH_EXEC_DATA has the AUTOGEN and FEEDBACK parameters. 2 GH_RES_CODE (Alpha only) GH_RES_CODE specifies the size in pages of the resident image code granularity hint region. GH_RES_CODE has the AUTOGEN and FEEDBACK attributes. 2 GH_RES_DATA (Alpha only) GH_RES_DATA specifies the size in pages of the resident image data granularity hint region. GH_RES_DATA has the AUTOGEN and FEEDBACK attributes. 2 GH_RSRVPGCNT GH_RSRVPGCNT specifies the number of pages in the resident image granularity hint region that the Install utility can use after the system has finished booting. If bit 2 of the LOAD_SYS_IMAGES parameter is set, the image LDR$WRAPUP releases all unused pages in the granularity hint region at the the end of system startup. The unused pages of the resident image granularity hint region are either reserved for future use, or given back to the free memory list. GH_RSRVPGCNT specifies the number of pages that LDR$WRAPUP attempts to leave in the resident image granularity hint region. If the GH_RSRVPGCNT number of pages is larger than the unused pages in the granularity hint region, the region is not expanded to accommodate the number of pages requested. GH_RSRVPGCNT is a FEEDBACK attribute parameter. 2 GLX_INST_TMO_ (Alpha Galaxy platforms only) GLX_INST_TMO is the time (in milliseconds) that an instance in a Galaxy sharing set can fail to increment its timeout value before the other sharing instances presume that the instance failed and remove it from the sharing set. The default is 20,000 milliseconds (20 seconds). 2 GLX_SHM_REG For Galaxy systems, GLX_SHM_REG is the number of shared memory region structures configured into the Galaxy Management Database (GMDB). If set to 0, the default number of shared memory regions are configured. 2 GROWLIM GROWLIM sets the number of pages that the system must have on the free-page list so that a process can add a page to its working set when it is above quota. GROWLIM has no effect if the process is below its working set quota. GROWLIM acts as a fast shutoff to the working set extent mechanism based on the system's free memory. GROWLIM has AUTOGEN, DYNAMIC, and MAJOR attributes. 2 IEEE_ADDRESS IEEE_ADDRESS is reserved for Compaq use only. 2 IEEE_ADDRESSH IEEE_ADDRESSH is reserved for Compaq use only. 2 IJOBLIM IJOBLIM sets the maximum number of interactive jobs that can be on the system concurrently. You can control the maximum number of concurrent interactive users on the system with the DCL command SET LOGINS/INTERACTIVE. IJOBLIM is a DYNAMIC parameter. 2 IMGIOCNT IMGIOCNT specifies the default number of pages of image I/O address space to be allocated for the image activator if not specified at program link time. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 IMGREG_PAGES (Alpha only) IMGREG_PAGES is the number of pages to reserve in P1 space for images to be installed with shareable address data. If IMGREG_PAGES is set to 0, no images are installed with shared address data. The default is 10,000 pages. For more information, see the INSTALL section in the OpenVMS System Management Utilities Reference Manual. 2 INTSTKPAGES (VAX only) INTSTKPAGES sets the size of the interrupt stack in pages. Each page on the interrupt stack requires a page of permanently resident memory. Use the default value of 6 unless interrupt-stack-not-valid exceptions occur. These may be caused by either an unusually large number of devices or a driver that requires a large amount of stack space. INTSTKPAGES has AUTOGEN, DYNAMIC, GEN, and MAJOR attributes. 2 IO_PREFER_CPUS (Alpha only) IO_PREFER_CPUS is a dynamic system parameter that controls the set of CPUs that are available for use as Fast Path preferred CPUs. IO_PREFER_CPUS is a CPU bit mask specifying the CPUs that are allowed to serve as preferred CPUs and that can thus be assigned a Fast Path port. CPUs whose bit is set in the IO_PREFER_CPUS bit mask are enabled for Fast Path port assignment. IO_PREFER_CPUS defaults to -1, which specifies that all CPUs are allowed to be assigned Fast Path ports. You might want to disable the primary CPU from serving as a preferred CPU by clearing its bit in IO_PREFER_CPUS. This reserves the primary CPU for non-Fast-Path IO operations to use. Changing the value of IO_PREFER_CPUS causes the FASTPATH_SERVER process to execute the automatic assignment algorithm that spreads Fast Path ports evenly among the new set of usable CPUs. For additional information, see FAST_PATH and FAST_PATH_PORTS. 2 IOTA IOTA specifies the amount of time (in 10-millisecond units) to charge to the current residence quantum for each voluntary wait. The correct value approximates the cost of a disk I/O neglecting wait time. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 JBOBLIM This parameter is no longer in use. 2 JOBCTLD System managers do not usually alter JOBCTLD; this word of debug flags is used in rolling upgrades of OpenVMS. If bit 0 is set, the queue manager does not start. The default is 0. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 KFILSTCNT KFILSTCNT is no longer used on VAX systems and is not used on Alpha systems. 2 KSTACKPAGES (Alpha only) KSTACKPAGES controls the number of pages allocated for process kernel stacks. 2 LAMAPREGS (VAX only) LAMAPREGS sets the number of UNIBUS map registers allocated to an LPA11 driver when the driver is loaded, and limits the registers for the driver to that number. A value of 0 permits dynamic allocation of an unlimited number of registers. LAMAPREGS has the GEN attribute. 2 LAN_FLAGS (Alpha only) LAN_FLAGS is a bit mask used to enable features in the local area networks port drivers and support code. The default value for LAN_FLAGS is 0. The bit definitions are as follows: Bit Description Bit 0 The default of zero indicates that ATM devices run in SONET mode. If set to 1, this bit indicates ATM devices run in SDH mode. Bit 1 If set, this bit enables a subset of the ATM trace and debug messages in the LAN port drivers and support code. Bit 2 If set, this bit enables all ATM trace and debug messages in the LAN port drivers and support code. Bit 3 If set, this bit runs UNI 3.0 over all ATM adapters. Bit 4 If set, this bit runs UNI 3.1 over all ATM adapters. Bit 5 If set, disables autoconfiguration over all Gigabit Ethernet Adapters. Bit 6 If set, enables the use of jumbo frames over all Gigabit Ethernet Adapters. LAN_FLAGS is a DYNAMIC parameter. 2 LCKMGR_CPUID (Alpha only) The LCKMGR_CPUID parameter controls the CPU that the Dedicated CPU Lock Manager runs on. This is the CPU that the LCKMGR_SERVER process will utilize if you turn this feature on with the LCKMGR_MODE system parameter. If the specified CPU ID is either the primary CPU or a non- existent CPU, the LCKMGR_SERVER process will utilize the lowest non-primary CPU. For more information, see the LCKMGR_MODE system parameter. LCKMGR_CPUID is a DYNAMIC parameter. 2 LCKMGR_MODE (Alpha only) The LCKMGR_MODE parameter controls usage of the Dedicated CPU Lock Manager. Setting LCKMGR_MODE to a number greater than zero (0) indicates the number of CPUs that must be active before the Dedicated CPU Lock Manager is turned on. The Dedicated CPU Lock Manager performs all locking operations on a single dedicated CPU. This can improve system performance on large SMP systems with high MP_Synch associated with the lock manager. For more information about usage of the Dedicated CPU Lock Manager, see the OpenVMS Performance Management. Specify one of the following: Value Description 0 Indicates the Dedicated CPU Lock Manager is off. (The default.) >0 Indicates the number of CPUs that must be active before the Dedicated CPU Lock Manager is turned on. LCKMGR_MODE is a DYNAMIC parameter. 2 LGI_BRK_DISUSER LGI_BRK_DISUSER turns on the DISUSER flag in the UAF record when an attempted break-in is detected, thus permanently locking out that account. The parameter is off (0) by default. You should set the parameter (1) only under extreme security watch conditions, because it results in severely restricted user service. LGI_BRK_DISUSER is a DYNAMIC parameter. 2 LGI_BRK_LIM LGI_BRK_LIM specifies the number of failures that can occur at login time before the system takes action against a possible break-in. The count of failures applies independently to login attempts by each user name, terminal, and node. Whenever login attempts from any of these sources reach the break-in limit specified by LGI_BRK_LIM, the system assumes it is under attack and initiates evasive action as specified by the LGI_HID_TIM parameter. The minimum value is 1. The default value is usually adequate. LGI_BRK_LIM is a DYNAMIC parameter. 2 LGI_BRK_TERM LGI_BRK_TERM causes the terminal name to be part of the association string for the terminal mode of break-in detection. When LGI_BRK_TERM is set to off (0), the processing considers the local or remote source of the attempt, allowing break-in detection to correlate failed access attempts across multiple terminal devices. When set to on (1), LGI_BRK_TERM assumes that only local hard-wired or dedicated terminals are in use and causes breakin detection processing to include the specific local terminal name when examining and correlating break-in attempts. Ordinarily, LGI_BRK_TERM should be set to off (0) when physical terminal names are created dynamically, such as when network protocols like LAT and Telnet are in use. LGI_BRK_TERM is a DYNAMIC parameter. 2 LGI_BRK_TMO LGI_BRK_TMO specifies the length of the failure monitoring period. This time increment is added to the suspect's expiration time each time a login failure occurs. Once the expiration period passes, prior failures are discarded, and the suspect is given a clean slate. LGI_BRK_TMO is a DYNAMIC parameter. 2 LGI_CALLOUTS LGI_CALLOUTS specifies the number of installation security policy callout modules to be invoked at each login. LGI_CALLOUTS must be set to 0 unless callout modules are present. LGI_CALLOUTS is a DYNAMIC parameter. 2 LGI_HID_TIM LGI_HID_TIM specifies the number of seconds that evasive action persists following the detection of a possible break-in attempt. The system refuses to allow any logins during this period, even if a valid user name and password are specified. LGI_HID_TIM is a DYNAMIC parameter. 2 LGI_PWD_TMO LGI_PWD_TMO specifies, in seconds, the period of time a user has to enter the correct system password (if used). LGI_PWD_TMO also establishes the timeout period for users to enter their personal account passwords at login time. Also, when using the SET PASSWORD command, LGI_PWD_TMO specifies the period of time the system waits for a user to type in a new password, an old password, and the password verification. LGI_PWD_TMO is a DYNAMIC parameter. 2 LGI_RETRY_LIM LGI_RETRY_LIM specifies the number of retry attempts allowed users attempting to log in. If this parameter is greater than 0, and a legitimate user fails to log in correctly because of typing errors, the user does not automatically lose the carrier. Instead (provided that LGI_RETRY_TMO has not elapsed), by pressing the Return key, the user is prompted to enter the user name and password again. Once the specified number of attempts has been made without success, the user loses the carrier. As long as neither LGI_BRK_LIM nor LGI_BRK_TMO has elapsed, the user can dial in again and reattempt login. LGI_RETRY_LIM is a DYNAMIC parameter. 2 LGI_RETRY_TMO LGI_RETRY_TMO specifies the number of seconds allowed between login retry attempts after each login failure. (Users can initiate login retries by pressing the Return key.) This parameter is intended to be used with the LGI_RETRY_LIM parameter; it allows dialup users a reasonable amount of time and number of opportunities to attempt logins before they lose the carrier. LGI_RETRY_TMO is a DYNAMIC parameter. 2 LNMPHASHTBL LNMPHASHTBL sets the size of the process logical name hash table. Logical names are hashed using a function of the name length and contents. The LNMPHASHTBL parameter determines the number of entries for process-private logical names. The recommended setting is the average number of process-private logical names. Note that the hashed values are rounded up to the nearest power of 2. LNMPHASHTBL has the GEN attribute. On VAX systems, LNMPHASHTBL is also an AUTOGEN-altered parameter. 2 LNMSHASHTBL LNMSHASHTBL sets the size of the system logical name hash table. Logical names are hashed using a function of the name length and contents. The LNMSHASHTBL parameter determines the number of entries for shareable logical names. These names include all names from the system, group, and job logical name tables. The recommended setting allows one to four logical names per hash table entry. The default setting is usually adequate, unless your installation has a large number of groups, or many jobs are active simultaneously. In that case, an increase in the value of the next higher power of 2 might improve logical name translation performance. Note that the hashed values are rounded up to the nearest power of 2. LNMSHASHTBL has the AUTOGEN, FEEDBACK, and GEN attributes. 2 LOAD_PWD_POLICY LOAD_PWD_POLICY controls whether the SET PASSWORD command attempts to use site-specific password policy routines, which are contained in the shareable image SYS$LIBRARY:VMS$PASSWORD_ POLICY.EXE. The default is 0, which indicates not to use policy routines. 2 LOAD_SYS_IMAGES This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. LOAD_SYS_IMAGES controls the loading of system images described in the system image data file, VMS$SYSTEM_IMAGES. This parameter is a bit mask. On VAX systems, the following bit is defined: Bit Description 0 (SGN$V_LOAD_SYS_IMAGES) Enables loading alternate execlets specified in VMS$SYSTEM_IMAGES.DATA. On Alpha systems, the following bits are defined: Bit Description 0 (SGN$V_LOAD_SYS_IMAGES) Enables loading alternate execlets specified in VMS$SYSTEM_IMAGES.DATA. 1 (SGN$V_EXEC_SLICING) Enables executive slicing. 2 (SGN$V_RELEASE_PFNS) Enables releasing unused portions of the Alpha huge pages. These bits are on by default. Using conversational bootstrap exec slicing can be disabled. On Alpha systems, LOAD_SYS_IMAGES is an AUTOGEN parameter. 2 LOCKDIRWT LOCKDIRWT determines the portion of lock manager directory that this system handles. The default value is usually adequate. LOCKDIRWT is an AUTOGEN parameter. 2 LOCKIDTBL LOCKIDTBL sets the initial number of entries in the system Lock ID table and defines the amount by which the Lock ID table is extended whenever the system runs out of locks. One entry must exist for each lock in the system; each entry requires 4 bytes. For simple timesharing systems, the default value is adequate. If your application uses many locks, as in the case of heavy RMS file sharing or a database management application, you should increase this parameter. When you change the value of LOCKIDTBL, examine the value of RESHASHTBL and change it if necessary. The OpenVMS Lock Management facility is described in the OpenVMS Programming Concepts Manual. You can monitor locks with the MONITOR LOCK command of the Monitor utility. LOCKIDTBL has the AUTOGEN, FEEDBACK, and MAJOR attributes. 2 LOCKIDTBL_MAX LOCKIDTBL_MAX is obsolete beginning with OpenVMS Version 7.1. 2 LOCKRETRY LOCKRETRY establishes the number of attempts made to lock a multiprocessor data structure. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 LONGWAIT LONGWAIT defines how much real time (in seconds) must elapse before the swapper considers a process to be temporarily idle. This parameter is applied to local event flag (LEF) and hibernate (HIB) waits to detect such conditions as an inactive terminal or ACP. LONGWAIT has the DYNAMIC, GEN, and MAJOR attributes. On Alpha systems, LONGWAIT is also an AUTOGEN-altered parameter. 2 LRPCOUNT This parameter has been obsolete since OpenVMS Version 6.0. 2 LRPSIZE This parameter has been obsolete since OpenVMS Version 6.0. 2 MAXBOBMEM (Alpha only) MAXBOBMEM defines the maximum amount of physical memory, measured in pagelets, that can be associated with a single buffer object created by a process in user mode. The default value of 0 means there is no system-imposed limit on the size of a buffer object. MAXBOBMEM is a DYNAMIC parameter. Other MAXBOB* parameters are obsolete in OpenVMS Version 7.3. 2 MAXBUF MAXBUF sets the maximum allowable size for any single buffered I/O packet. Buffered I/O packets are allocated from the permanently resident nonpaged dynamic pool. The terminal, mailbox, and printer device drivers are examples of device drivers that perform buffered I/O. The number of bytes specified in the I/O request plus the size of a driver-dependent and function-dependent header area determine the required buffered I/O packet size. The size of the header area is a minimum of 16 bytes; there is no absolute upper limit. However, this header area is usually a few hundred bytes in size. On OpenVMS VAX systems beginning with Version 7.1, the default value is 4112. The default value on OpenVMS Alpha systems continues to be 8192. The maximum value of MAXBUF is 64000 bytes. MAXBUF is a DYNAMIC parameter. 2 MAXCLASSPRI If class scheduling is enabled, MAXCLASSPRI sets the maximum range in the priority range of class-scheduled processes. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. MAXCLASSPRI is a DYNAMIC parameter. 2 MAXPROCESSCNT MAXPROCESSCNT sets the number of process entry slots allocated at bootstrap time. One slot is required for each concurrent process on the system. Each slot requires 6 bytes of permanently resident memory. The default value is normally configured to allow you to create the desired number of processes. If the following message appears, you need to increase the value of MAXPROCESSCNT: %SYSTEM-F-NOSLOT, No PCB to create process MAXPROCESSCNT has the AUTOGEN, FEEDBACK, GEN, and MAJOR attributes. 2 MAXQUEPRI MAXQUEPRI determines the highest scheduling priority that can be assigned to jobs entered in batch and output (printer, server, and terminal) queues without the submitter process having OPER or ALTPRI privilege. The value of this parameter can range from 0 to 255; the default is 100. The value of MAXQUEPRI should be greater than or equal to DEFQUEPRI. NOTE MAXQUEPRI refers to relative queue scheduling priority, not to the execution priority of the job. MAXQUEPRI is a DYNAMIC parameter. 2 MAXSYSGROUP MAXSYSGROUP sets the highest value that a group number can have and still be classified as a system UIC group number. Note that the specification is not in octal unless preceded by the %O radix indicator. This parameter is normally left at 8 (10 octal). MAXSYSGROUP is a DYNAMIC parameter. 2 MC_SERVICES_P0 (Alpha only) MC_SERVICES_P0 controls whether other MEMORY CHANNEL nodes in the cluster continue to run if this node bugchecks or shuts down. A value of 1 causes other nodes in the MEMORY CHANNEL cluster to crash with bugcheck code MC_FORCED_CRASH if this node bugchecks or shuts down. The default value is 0. A setting of 1 is intended only for debugging purposes; the parameter should otherwise be left at its default value. MC_SERVICES_P0 is a DYNAMIC parameter. 2 MC_SERVICES_P1 (Alpha only) This special parameter is reserved for Compaq use. Its value must be the same on all nodes connected by MEMORY CHANNEL. MC_SERVICES_P1 is a DYNAMIC parameter. 2 MC_SERVICES_P2 (Alpha only) MC_SERVICES_P2 specifies whether to load the PMDRIVER (PMA0) MEMORY CHANNEL cluster port driver. PMDRIVER is a new driver that serves as the MEMORY CHANNEL cluster port driver. It works together with MCDRIVER (the MEMORY CHANNEL device driver and driver interface) to provide MEMORY CHANNEL clustering. If PMDRIVER is not loaded, cluster connections are not made over the MEMORY CHANNEL interconnect. The default value is 1, which causes PMDRIVER to be loaded when you boot the system. When you run CLUSTER_CONFIG.COM and select the MEMORY CHANNEL option, PMDRIVER is loaded automatically when you reboot the system. Compaq recommends that this value not be changed. This parameter value must be the same on all nodes connected by MEMORY CHANNEL. 2 MC_SERVICES_P3 (Alpha only) MC_SERVICES_P3 specifies the maximum number of tags supported. The maximum value is 2048, and the minimum value is 100. The default value is 800. Compaq recommends that this value not be changed. This parameter value must be the same on all nodes connected by MEMORY CHANNEL. MC_SERVICES_P3 is a DYNAMIC parameter. 2 MC_SERVICES_P4 (Alpha only) MC_SERVICES_P4 specifies the maximum number of regions supported. The maximum value is 4096, and the minimum value is 100. The default value is 200. Compaq recommends that this value not be changed. This parameter value must be the same on all nodes connected by MEMORY CHANNEL. 2 MC_SERVICES_P5 (Alpha only) MC_SERVICES_P5 is reserved for Compaq use only and must remain at the default value of 8000000. This value must be the same on all nodes connected by MEMORY CHANNEL. MC_SERVICES_P5 is a DYNAMIC parameter. 2 MC_SERVICES_P6 (Alpha only) MC_SERVICES_P6 specifies MEMORY CHANNEL message size, the body of an entry in a free queue, or a work queue. The maximum value is 65536, and the minimum value is 544. The default value is 992. This value is suitable in all cases except for systems with highly constrained memory. For such systems, you can reduce the memory consumptions of MEMORY CHANNEL by slightly reducing the default value of 992. The value of MC_ SERVICES_P6 must always be equal to or greater than the result of the following calculations: 1. Select the larger of SCS_MAXMSG and SCS_MAXDG. 2. Round that value up to the next quadword. The value of MC_SERVICES_P6 must be the same on all nodes connected by MEMORY CHANNEL. 2 MC_SERVICES_P7 (Alpha only) MC_SERVICES_P7 specifies whether to suppress or display messages about MEMORY CHANNEL activities on this node. This parameter can be set to a value of 0, 1, or 2: o A value of 0 indicates nonverbose mode: no informational messages appear on the console or in the error log. o A value of 1 indicates verbose mode: informational messages from both MCDRIVER and PMDRIVER appear on the console and in the error log. o A value of 2 provides the same output as a value of 1, with the addition of PMDRIVER stalling and recovery messages. The default value is 0. Compaq recommends that this value not be changed except while debugging MEMORY CHANNEL problems or adjusting the MC_SERVICES_P9 parameter. MC_SERVICES_P7 is a DYNAMIC parameter. 2 MC_SERVICES_P8 (Alpha only) MC_SERVICES_P8 is reserved for Compaq use only and must remain at the default value of 0. The value must be the same on all nodes connected by MEMORY CHANNEL. 2 MC_SERVICES_P9 (Alpha only) MC_SERVICES_P9 specifies the number of initial entries in a single channel's free queue. The maximum value is 2048, and the minimum value is 10. Note that MC_SERVICES_P9 is not a dynamic parameter; you must reboot the system after each change for that change to take effect. The default value is 150. Compaq recommends that this value not be changed. The value of MC_SERVICES_P9 must be the same on all nodes connected by MEMORY CHANNEL. 2 MINCLASSPRI If class scheduling is enabled, MINCLASSPRI sets the minimum range in the priority range of class-scheduled processes. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. MINCLASSPRI is a DYNAMIC parameter. 2 MINPRPRI This parameter is not used on OpenVMS VAX or Alpha systems. 2 MINWSCNT The value specified by MINWSCNT is added to the size of the process header to establish the minimum working set size. On VAX systems, MINWSCNT sets the minimum number of fluid pages (pages not locked in the working set) required for the execution of a process. The value of MINWSCNT must provide sufficient space to execute any VAX instruction. Theoretically, the longest instruction requires 52 pages; however, all code can run with 20 fluid pages. An insufficient value may inhibit system performance or even put a process into an infinite loop on some instructions. On Alpha systems, MINWSCNT sets the minimum number of pages required for the execution of a process. The default value is 20; the minimum value is 10. MINWSCNT is an AUTOGEN parameter. 2 MMG_CTLFLAGS MMG_CTLFLAGS is a bit mask used to enable and disable proactive memory reclamation mechanisms. Beginning with OpenVMS Version 7.2, you can control when memory is tested. This helps reduce the time between when you turn on the system and when you log in to an AlphaServer 4100 computer. Bit 2 in the parameter controls deferred memory testing. The following bit mask values are defined: Bit Description 0 Reclamation enabled by trimming from periodically executing, but otherwise idle processes. This occurs when the size of the free list drops below two times FREEGOAL. 1 Reclamation enabled by outswapping processes that have been idle for longer than LONGWAIT seconds. This occurs when the size of the free list drops below FREELIM. 2 Controls deferred memory testing: o If the bit is clear (the default), OpenVMS tests memory in the background and not necessarily before the bootstrap process has completed. o If the bit is set, all memory is tested by the end of EXEC_INIT in the system bootstrap process (that is, before IPL is lowered from 31). 3-7 Reserved for future use. MMG_CTLFLAGS is an AUTOGEN and DYNAMIC parameter. 2 MPDEV_D1 (Alpha only) MPDEV_D1 is reserved for use by the operating system. 2 MPDEV_ENABLE (Alpha only) MPDEV_ENABLE enables the formation of multipath sets when set to ON (1). If set to OFF (0), the formation of additional multipath sets is disabled. However, existing multipath sets remain in effect. The default is ON. 2 MPDEV_LCRETRIES (Alpha only) MPDEV_LCRETRIES controls the number of times the system retries locally connected paths before moving on to local unconnected paths or to an MSCP served path to the device. The valid range for retries is 1 through 256. The default is 1. 2 MPDEV_POLLER (Alpha only) MPDEV_POLLER enables polling of the paths to multipath set members when set to ON (1). Polling allows early detection of errors on inactive paths. If a path becomes unavailable or returns to service, the system manager is notified with an OPCOM message. If set to OFF (0), multipath polling is disabled. The default is ON. 2 MPDEV_REMOTE (Alpha only) MPDEV_REMOTE enables MSCP served disks to become members of a multipath set when set to ON (1). If set to OFF (0), only local paths to a SCSI or Fibre Channel device will be used in the formation of additional multipath sets. However, setting this parameter to OFF will not have any effect on existing multipath sets that have remote paths. The default is OFF. For OpenVMS Alpha Version 7.3, this parameter must remain set to the default value of OFF (0). This restriction will be removed in a future release of OpenVMS. 2 MPW_HILIMIT MPW_HILIMIT sets an upper limit for the modified-page list. When the list accumulates the number of pages specified by this limit, writing of the list begins. The pages that are written are then transferred to the free-page list. If MPW_HILIMIT is too low, excessive page faulting can occur from the page file. If it is too high, too many physical pages can be consumed by the modified-page list. If you increase MPW_HILIMIT, you might also need to increase MPW_WAITLIMIT. Note that if MPW_WAITLIMIT is less than MPW_HILIMIT, a system deadlock occurs. The values for the two parameters are usually equal. MPW_HILIMIT has the AUTOGEN and GEN attributes. 2 MPW_IOLIMIT MPW_IOLIMIT specifies the number of outstanding I/Os to the modified-page writer. On Alpha systems, MPW_IOLIMIT is an AUTOGEN-altered parameter. 2 MPW_LOLIMIT MPW_LOLIMIT sets a lower limit for the modified-page list. When writing of the list causes the number of pages on the list to drop to or below this limit, writing stops. MPW_LOLIMIT ensures that a certain number of pages are available on the modified-page list for page faults. If the number is too small, the caching effectiveness of the modified-page list is reduced. If it is too high, less memory is available for processes, so that swap (and page) may increase. MPW_LOLIMIT has the AUTOGEN and GEN attributes. 2 MPW_LOWAITLIMIT MPW_LOWAITLIMIT specifies the threshold at which processes in the miscellaneous wait state MPWBUSY are allowed to resume. MPW_LOWAITLIMIT increases system performance for fast processors with large memories by reducing the amount of time processes spend in the MPWBUSY wait state. MPW_LOWAITLIMIT has the AUTOGEN and DYNAMIC attributes. 2 MPW_PRIO MPW_PRIO sets the priority of I/O transfers initiated by the modified page writer. The maximum value is 31, the minimum is 0, and the default is 4. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 MPW_THRESH MPW_THRESH sets a lower bound of pages that must exist on the modified-page list before the swapper writes this list to acquire free pages. If this requirement is met, the swapper tries to write the modified-page list rather than taking pages away from or swapping out a process. MPW_THRESH has the DYNAMIC attribute. On Alpha systems, MPW_ THRESH is also an AUTOGEN parameter. 2 MPW_WAITLIMIT MPW_WAITLIMIT sets the number of pages on the modified-page list that causes a process to wait until the next time the modified- page writer writes the modified list. This parameter limits the rate at which any single process can produce modified pages. If this value is less than MPW_HILIMIT, a system deadlock occurs. The value for this parameter is normally equal to MPW_HILIMIT. MPW_WAITLIMIT has the AUTOGEN and DYNAMIC attributes. 2 MPW_WRTCLUSTER MPW_WRTCLUSTER sets the number of pages to be written during one I/O operation from the modified-page list to the page file or a section file. The actual size of the cluster may be limited by the number of pages available for the I/O operation. This parameter can range in value from 16 to 120, in multiples of 8. Each page in the cluster requires 6 bytes of permanently resident memory. If MPW_WRTCLUSTER is too small, it takes many I/O operations to empty the modified-page list. If MPW_WRTCLUSTER is too large for the speed of the disk that holds the page file, other I/O operations are held up for the modified-page list write. On VAX systems, the MPW_WRTCLUSTER default value and maximum value is 120 512-byte pages; its minimum value is 16 512-byte pages. On Alpha systems, the MPW_WRTCLUSTER default value is 64 8192- byte pages; its maximum value is 512 8192-byte pages; and its minimum value is 16 8192-byte pages. MPW_WRTCLUSTER has the AUTOGEN and GEN attributes. 2 MSCP_BUFFER This buffer area is the space used by the server to transfer data between client systems and local disks. On VAX systems, MSCP_BUFFER specifies the number of pages to be allocated to the MSCP server's local buffer area. On Alpha systems, MSCP_BUFFER specifies the number of pagelets to be allocated to the MSCP server's local buffer area. MSCP_BUFFER is an AUTOGEN and FEEDBACK parameter. 2 MSCP_CMD_TMO MSCP_CMD_TMO is the time in seconds that the OpenVMS MSCP server uses to detect MSCP command timeouts. The MSCP Server must complete the command within a built-in time of approximately 40 seconds plus the value of the MSCP_CMD_TMO parameter. The MSCP_CMD_TMO default value of 0 is normally adequate. A value of 0 provides the same behavior as in previous releases of OpenVMS (which did not have an MSCP_CMD_TMO system parameter). A nonzero setting increases the amount of time before an MSCP command times out. If command timeout errors are being logged on client nodes, setting the parameter to a nonzero value on OpenVMS servers reduces the number of errors logged. Increasing the value of this parameter reduces the numb client MSCP command timeouts and increases the time it takes to detect faulty devices. If you need to decrease the number of command timeout errors, Compaq recommends that you set an initial value of 60. If timeout errors continue to be logged, you can increase this value in increments of 20 seconds. MSCP_CMD_TMO is a DYNAMIC parameter. 2 MSCP_CREDITS MSCP_CREDITS specifies the number of outstanding I/O requests that can be active from one client system. 2 MSCP_LOAD MSCP_LOAD controls the loading of the MSCP server during a system boot. Specify one of the following values: Value Description 0 Do not load the MSCP server. This is the default value. 1 Load the MSCP server and serve disks as specified by the MSCP_SERVE_ALL parameter. MSCP_LOAD has the AUTOGEN attribute. 2 MSCP_SERVE_ALL MSCP_SERVE_ALL is a bit mask that controls disk serving in an OpenVMS Cluster. A disk is served regardless of its allocation class unless bit 3 has a value of 1. Starting with OpenVMS Version 7.2, the serving types are implemented as a bit mask. To specify the type of serving your system will perform, locate the type you want in the following table and specify its value. For some systems, you may want to specify two serving types, such as serving the system disk and serving locally attached disks. To specify such a combination, add the values of each type, and specify the sum. In a mixed-version cluster that includes any systems running OpenVMS Version 7.1-x or earlier, serving all available disks is restricted to serving all disks except those whose allocation class does not match the system's node allocation class (pre- Version 7.2). To specify this type of serving, use the value 9 (which sets bit 0 and bit 3). The following table describes the serving type controlled by each bit and its decimal value. Bit and Value When Set Description Bit 0 Serve all available disks (locally attached and those (1) connected to HSx and DSSI controllers). Disks with allocation classes that differ from the system's allocation class (set by the ALLOCLASS parameter) are also served if bit 3 is not set. Bit 1 Serve locally attached (non-HSx and DSSI) disks. (2) Bit 2 Serve the system disk. This is the default setting. (4) This setting is important when other nodes in the cluster rely on this system being able to serve its system disk. This setting prevents obscure contention problems that can occur when a system attempts to complete I/O to a remote system disk whose system has failed. Bit 3 Restrict the serving specified by bit 0. All disks (8) except those with allocation classes that differ from the system's allocation class (set by the ALLOCLASS parameter) are served. This is pre-Version 7.2 behavior. If your cluster includes systems running OpenVMS 7.1-x or earlier, and you want to serve all available disks, you must specify 9, the result of setting this bit and bit 0. Although the serving types are now implemented as a bit mask, the values of 0, 1, and 2, specified by bit 0 and bit 1, retain their original meanings: o 0 - Do not serve any disks (the default for earlier versions of OpenVMS). o 1 - Serve all available disks. o 2 - Serve only locally attached (non-HSx and non-DSSI) disks. If the MSCP_LOAD system parameter is 0, MSCP_SERVE_ALL is ignored. 2 MULTIPROCESSING MULTIPROCESSING controls the loading of the system synchronization image. Specify one of the following values: Value Description 0 Load the uniprocessing synchronization image SYSTEM_SYNCHRONIZATION_UNI.EXE. 1 If the CPU type is capable of SMP and two or more CPUs are present on the system, load the full-checking multiprocessing synchronization image SYSTEM_SYNCHRONIZATION.EXE. Otherwise, load the uniprocessing synchronization image SYSTEM_SYNCHRONIZATION_UNI.EXE. 2 Always load the full-checking version SYSTEM_SYNCHRONIZATION.EXE, regardless of system configuration or CPU availability. 3 If the CPU type is capable of SMP and two or more CPUs are present on the system, load the optimized streamlined multiprocessing image: o On VAX systems, this image is SYSTEM_SYNCHRONIZATION_SPC.EXE. o On Alpha systems, this image is SYSTEM_SYNCHRONIZATION_MIN.EXE. Otherwise, load the uniprocessing synchronization image SYSTEM_SYNCHRONIZATION_UNI.EXE. The default value is 3. 4 Always load the streamlined multiprocessing image SYSTEM_SYNCHRONIZATION_MIN.EXE, regardless of system configuration or CPU availability. Setting the SYSTEM_CHECK parameter to 1 has the effect of setting MULTIPROCESSING to 2. 2 MULTITHREAD MULTITHREAD controls the availability of kernel threads functions. Specify one of the following values: Value Description 0 Both Thread Manager upcalls and the creation of multiple kernel threads are disabled. 1 Thread Manager upcalls are enabled; the creation of multiple kernel threads is disabled. 2-256 Both Thread Manager upcalls and the creation of (Alpha multiple kernel threads are enabled. The number only) specified represents the maximum number of kernel threads that can be created for a single process. The maximum value for MULTITHREAD is 256. MULTITHREAD is an AUTOGEN parameter. 2 MVTIMEOUT MVTIMEOUT is the time in seconds that a mount verification attempt continues on a given disk volume. If the mount verification does not recover the volume within that time, the I/O operations outstanding to the volume terminate abnormally. MVTIMEOUT is a DYNAMIC parameter. On Alpha systems, MVTIMEOUT is also an AUTOGEN parameter. 2 NET_CALLOUTS NET_CALLOUTS is normally set to 0. A value of 255 indicates that no attempt is to be made to assign a new proxy connection to an active server, but that a new process must be started to invoke the installation security policy callout modules in LOGINOUT.EXE. Values 1 through 254 are reserved for future use. NET_CALLOUTS is a DYNAMIC parameter. 2 NISCS_CONV_BOOT NISCS_CONV_BOOT controls whether a conversational boot is permitted during a remote system boot. The default value of 0 specifies that conversational boots are not permitted. 2 NISCS_LAN_OVRHD Beginning in OpenVMS Version 7.3, this parameter is obsolete. 2 NISCS_LOAD_PEA0 NISCS_LOAD_PEA0 controls whether the NI-SCS port driver PEDRIVER is loaded during system boot. The default of 0 specifies that the PEDRIVER is not loaded. 2 NISCS_MAX_PKTSZ This parameter specifies an upper limit on the size, in bytes, of the user data area in the largest packet sent by NISCA on any local area network (LAN). NISCS_MAX_PKTSZ allows the system manager to change the packet size used for cluster communications on network communication paths. PEDRIVER automatically allocates memory to support the largest packet size that is usable by any virtual circuit connected to the system up to the limit set by this parameter. Its default values are different for OpenVMS Alpha and OpenVMS VAX: o On Alpha, to optimize performance, the default value is the largest packet size currently supported by OpenVMS. o On VAX, to conserve memory, the default value is the Ethernet packet size. PEDRIVER uses NISCS_MAX_PKTSZ to compute the maximum amount of data to transmit in any LAN packet: LAN packet size <= LAN header (padded Ethernet format) + NISCS_MAX_PKTSZ + NISCS checksum (only if data checking is enabled) + LAN CRC or FCS The actual packet size automatically used by PEDRIVER might be smaller than the NISCS_MAX_PKTSZ limit for any of the following reasons: o On a per-LAN path basis, if PEdriver determines that the LAN path between two nodes, including the local and remote LAN adapters and intervening LAN equipment, can only convey a lesser size. In other words, only nodes with large-packet LAN adapters connected end-to-end by large-packet LAN equipment can use large packets. Nodes connected to large-packet LANs but having an end-to-end path that involves an Ethernet segment restrict packet size to that of an Ethernet packet (1498 bytes). o For performance reasons, PEDRIVER might further limit the upper bound on packet size so that the packets can be allocated from a lookaside list in the nonpaged pool. The actual memory allocation includes the required data structure overhead used by PEDRIVER and the LAN drivers, in addition to the actual LAN packet size. The following table shows the minimum NISCS_MAX_PKTSZ value required to use the maximum packet size supported by specified LAN types. Type of LAN Minimum Value for NISCS_MAX_PKTSZ Ethernet 1498 FDDI 4468 Gigabit 7532 Ethernet ATM 7606 On Alpha systems, NISCS_MAX_PKTSZ is an AUTOGEN parameter. 2 NISCS_PORT_SERV NISCS_PORT_SERV provides flag bits for PEDRIVER port services. Setting bits 0 and 1 (decimal value 3) enables data checking. The remaining bits are reserved for future use. NISCS_PORT_SERV has the AUTOGEN attribute. 2 NJOBLIM NJOBLIM establishes the limit for network jobs. The maximum number of jobs is 1024. The minimum is 0, and the default is 16. NJOBLIM is a DYNAMIC parameter. 2 NOAUTOCONFIG NOAUTOCONFIG controls whether all devices are automatically configured when the system boots. The default value of 0 sets the system to automatically configure all devices. Set NOAUTOCONFIG to 1 (no automatic configuration) only for debugging purposes. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. NOAUTOCONFIG is a DYNAMIC parameter. 2 NOCLUSTER NOCLUSTER controls whether page read clustering is inhibited when the system boots. Set NOCLUSTER to 1 (inhibit page read clustering) only for debugging purposes. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 NOPGFLSWP If enabled, NOPGFLSWP disables swapping into page files. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 NPAGECALC NPAGECALC controls whether the system automatically calculates the initial size for nonpaged dynamic memory. Compaq sets the default value of NPAGECALC to 1 only during the initial boot after an installation or upgrade. When the value of NPAGECALC is 1, the system calculates an initial value for the NPAGEVIR and NPAGEDYN system parameters. This calculated value is based on the amount of physical memory in the system. NPAGECALC's calculations do not reduce the values of NPAGEVIR and NPAGEDYN from the values you see or set at the SYSBOOT prompt. However, NPAGECALC's calculation might increase these values. AUTOGEN sets NPAGECALC to 0. NPAGECALC should always remain 0 after AUTOGEN has determined more refined values for the NPAGEDYN and NPAGEVIR system parameters. 2 NPAGEDYN NPAGEDYN sets the size of the nonpaged dynamic pool in bytes. This figure is rounded down to an integral number of pages. NPAGEDYN establishes the initial setting of the nonpaged pool size, but the pool size can be increased dynamically. To set a value for this parameter, use AUTOGEN initially, and then monitor the amount of space actually used with the DCL command SHOW MEMORY/POOL/FULL. For the benefit of OpenVMS VAX systems with limited physical memory, AUTOGEN logs a warning message in its report if NPAGEDYN exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33 percent of physical memory. AUTOGEN also limits its own calculated value for NPAGEDYN to 20 percent of physical memory and limits NPAGEVIR to 50 percent of physical memory. These calculated values are adequate for most workstations and systems with 16 or fewer megabytes of physical memory. If your system requires a larger value, you can override the AUTOGEN calculated values by setting higher values in MODPARAMS.DAT. NPAGEDYN has AUTOGEN, FEEDBACK, GEN, and MAJOR attributes. 2 NPAGERAD (Alpha only) NPAGERAD specifies the total number of bytes of nonpaged pool that will be allocated for Resource Affinity Domains (RADs) other than the base RAD. For platforms that have no RADs, NPAGERAD is ignored. Notice that NPAGEDYN specifies the total amount of nonpaged pool for all RADs. Also notice that the OpenVMS system might round the specified values higher to an even number of pages for each RAD, which prevents the base RAD from having too little nonpaged pool. For example, if the hardware is an AlphaServer GS160 with 4 RADs: NPAGEDYN = 6291456 bytes NPAGERAD = 2097152 bytes In this case, the OpenVMS system allocates a total of approximately 6,291,456 bytes of nonpaged pool. Of this amount, the system divides 2,097,152 bytes among the the RADs that are not the base RAD. The system then assigns the remaining 4,194,304 bytes to the base RAD. NPAGERAD has the GEN attribute. 2 NPAGEVIR NPAGEVIR defines the maximum size to which NPAGEDYN can be increased. If this value is too small, the system can hang. If NPAGEVIR is too large, the result is a penalty of 4 bytes per extra page on VAX and 8 bytes per extra page on Alpha. For the benefit of OpenVMS VAX systems with limited physical memory, AUTOGEN logs a warning message in its report if NPAGEDYN exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33 percent of physical memory. AUTOGEN also limits its own calculated value for NPAGEDYN to 20 percent of physical memory, and limits NPAGEVIR to 50 percent of physical memory. These calculated values are adequate for most workstations and systems with 16 or fewer megabytes of physical memory. If your system requires a larger value, you can override the AUTOGEN calculated values by setting higher values in MODPARAMS.DAT. NPAGEVIR has AUTOGEN and GEN attributes. 2 NPAG_AGGRESSIVE (Alpha only) NPAG_AGGRESSIVE is the percentage of packets on a nonpaged pool lookaside list that remain after the list is trimmed during aggressive reclamation. NPAG_AGGRESSIVE is a DYNAMIC parameter. 2 NPAG_BAP_MAX (Alpha only) NPAG_BAP_MAX is the maximum of bus addressable pool sizes requested. 2 NPAG_BAP_MAX_PA (Alpha only) NPAG_BAP_MAX_PA is the smallest of the maximum bus addressable pool physical addresses requested. 2 NPAG_BAP_MIN (Alpha only) NPAG_BAP_MIN is the minimum of bus addressable pool sizes requested. 2 NPAG_BAP_MIN_PA (Alpha only) NPAG_BAP_MIN_PA specifies the lowest physical address allowed within a bus addressable pool. 2 NPAG_GENTLE (Alpha only) NPAG_GENTLE is the percentage of packets on a nonpaged pool lookaside list remaining after the list is trimmed during gentle reclamation. NPAG_GENTLE is a DYNAMIC parameter. 2 NPAG_INTERVAL (Alpha only) NPAG_INTERVAL is the number of seconds between passes of nonpaged pool gentle reclamation. NPAG_INTERVAL is a DYNAMIC parameter. 2 NPAG_RING_SIZE (Alpha only) NPAG_RING_SIZE represents the number of entries in the ring buffer. 2 PAGEDYN PAGEDYN sets the size of the paged dynamic pool in bytes. The specified value is rounded down to an integral number of pages. Each page of paged dynamic pool adds 8 bytes of permanently resident memory to the system page table; the paged dynamic pool has no other direct memory requirements. The paged dynamic pool is used to allocate storage for shared logical names, resident image headers, known file list entries, and RMS file-sharing structures. Substantial amounts of space for the pool can be overallocated with little effect on system performance. The size of the paged pool can grow dynamically up to the maximum size that this parameter specifies. PAGEDYN has AUTOGEN, FEEDBACK, GEN, and MAJOR attributes. 2 PAGFILCNT On VAX systems, PAGFILCNT defines the maximum number of page files that can be installed. On Alpha systems, beginning in OpenVMS Version 7.3, this parameter is obsolete. 2 PAGTBLPFC PAGTBLPFC specifies (in pages) the maximum number of page tables to read to satisfy a fault for a nonresident page table. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 PAMAXPORT PAMAXPORT specifies the maximum port number to be polled on each CI and DSSI. The CI and DSSI port drivers poll to discover newly initialized ports or the absence/failure of previously responding remote ports. A system does not detect the existence of ports whose port numbers are higher than this parameter's value. Thus, set this parameter to a value that is equal to or greater than the highest port number being used on any CI or DSSI connected to the system. You can decrease this parameter to reduce polling activity if the hardware configuration has fewer than 16 ports. For example, if the CI or DSSI with the largest configuration has a total of 5 ports assigned to port numbers 0 through 4, you could set PAMAXPORT to 4. If CI or DSSI devices are not configured on your system, this parameter is ignored. The default for this parameter is 15 (poll for all possible ports 0 through 15). Compaq recommends that you set this parameter to the same value on each cluster computer. PAMAXPORT is a DYNAMIC parameter. 2 PANOPOLL Disables CI and DSSI polling for ports if set to 1. (The default is 0.) When PANOPOLL is set, a computer does not discover that another computer has shut down or powered down promptly and does not discover a new computer that has booted. This parameter is useful when you want to bring up a computer detached from the rest of the cluster for checkout purposes. PANOPOLL is functionally equivalent to uncabling the system from the DSSI or star coupler. This parameter does not affect OpenVMS Cluster communications by LAN. The default value of 0 is the normal setting and is required if you are booting from an HSC controller or if your system is joining an OpenVMS Cluster. This parameter is ignored if no CI or DSSI devices are configured on your system. PANOPOLL is a DYNAMIC parameter. 2 PANUMPOLL PANUMPOLL establishes the number of CI and DSSI ports to be polled each polling interval. The normal setting for PANUMPOLL is 16. On systems with less powerful CPUs, the parameter may be useful in applications sensitive to the amount of contiguous time that the system spends at IPL 8. Reducing PANUMPOLL reduces the amount of time spent at IPL 8 during each polling interval, while increasing the number of polling intervals needed to discover new or failed ports. If CI or DSSI devices are not configured on your system, this parameter is ignored. PANUMPOLL is a DYNAMIC parameter. 2 PAPOLLINTERVAL Specifies, in seconds, the polling interval the CI port driver uses to poll for a newly booted computer, a broken port-to-port virtual circuit, or a failed remote computer. This parameter trades polling overhead against quick response to virtual circuit failures. Compaq recommends that you use the default value for this parameter. Compaq recommends that you set this parameter to the same value on each cluster computer. PAPOLLINTERVAL is a DYNAMIC parameter. 2 PAPOOLINTERVAL Specifies, in seconds, the interval at which the port driver checks available nonpaged pool after a pool allocation failure. This parameter trades faster response to pool allocation failures against increased polling overhead. Compaq recommends that you use the default value for this parameter. If CI or DSSI devices are not configured on your system, this parameter is ignored. PAPOOLLINTERVAL is a DYNAMIC parameter. 2 PASANITY PASANITY controls whether the CI and DSSI port sanity timers are enabled to permit remote systems to detect a system that has been hung at IPL 8 or above for 100 seconds. It also controls whether virtual circuit checking gets enabled on the local system. The TIMVCFAIL parameter controls the time (1-99 seconds). PASANITY is normally set to 1 and should be set to 0 only when you are debugging with XDELTA or planning to halt the CPU for periods of 100 seconds or more. PASANITY is only semidynamic. A new value of PASANITY takes effect on the next CI or DSSI port reinitialization. If CI or DSSI devices are not configured on your system, this parameter is ignored. PASANITY is a DYNAMIC parameter. 2 PASTDGBUF The number of datagram receive buffers to queue initially for the cluster port driver's configuration poller. The initial value is expanded during system operation, if needed. Memory Channel devices ignore this parameter. PASTDGBUF is an AUTOGEN parameter. 2 PASTIMOUT The basic interval at which the CI port driver wakes up to perform time-based bookkeeping operations. It is also the period after which a timeout is declared if no response to a start handshake datagram has been received. If CI or DSSI devices are not configured on your system, this parameter is ignored. The default value should always be adequate. PASTIMOUT is a DYNAMIC parameter. 2 PE PE1, PE2, PE3, PE4, PE5, PE6 are reserved for Compaq use only. These parameters are for cluster algorithms and their usages can change from release to release. Compaq recommends using the default values for these special parameters. 2 PFCDEFAULT On VAX systems during execution of programs, PFCDEFAULT controls the number of image pages read from disk per I/O operation when a page fault occurs. The PFCDEFAULT maximum default value is 127 512-byte pages. On Alpha systems during execution of programs, PFCDEFAULT controls the number of image pagelets read from disk per I/O operation when a page fault occurs. The PFCDEFAULT maximum default value is 2032 512-byte pagelets (127 8192-byte Alpha pages). The read I/O operations can take place from an image file or from the page file. The actual size of the cluster can be less than PFCDEFAULT, depending on the size of image sections and the pattern of page references. The value should not be greater than one-fourth the default size of the average working set to prevent a single page fault from displacing a major portion of a working set. Too large a value for PFCDEFAULT can hurt system performance. PFCDEFAULT can be overridden on an image-by-image basis with the CLUSTER option of the OpenVMS linker. PFCDEFAULT has the AUTOGEN and DYNAMIC attributes. 2 PFN_COLOR_COUNT (Alpha only) PFN_COLOR_COUNT specifies the number of buckets (colors) into which all members of the zeroed page list and all unencumbered members of the free page list are sorted. OpenVMS Alpha systems might derive a preferred page color from a request to map a given virtual page and attempt to map that virtual page to a PFN of matching "color." This results in less variance in which cache blocks are used when accessing that page. This might or might not improve performance, depending on the application. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. If you increase this parameter, you must also increase the ZERO_LIST_HI system parameter. 2 PFRATH PFRATH specifies the page fault rate above which the limit of a working set is automatically increased. The unit of measure is the number of faults per 10 seconds of processor time. At a setting of 120, for example, the system automatically increases the limit of a working set if it is faulting more than 120 pages per 10 seconds. Decreasing the value of this parameter tends to increase the limits of the working sets, while increasing its value tends to decrease their limits. On VAX systems, the default value is 120 page faults every 10 seconds. On Alpha systems, the default value is 8 page faults every 10 seconds. PFRATH has the DYNAMIC and MAJOR attributes. On Alpha systems, PFRATH also is an AUTOGEN-altered parameter. 2 PFRATL PFRATL specifies the page fault rate below which the limit of a working set is automatically decreased. The unit of measure is the number of faults per 10 seconds of processor time. At a setting of 1, for example, the system automatically decreases the limit of a working set if it is faulting less than 1 page every 10 seconds. Increasing the value of this parameter tends to decrease the limits of the working sets, while decreasing its value tends to increase their limits. PFRATL has the AUTOGEN, DYNAMIC, and MAJOR attributes. 2 PHYSICAL_MEMORY (Alpha only) PHYSICAL_MEMORY specifies the amount of physical memory available for use. The default setting is -1, which equates to all memory in the system. Decreasing this parameter allows you to test smaller configurations of memory without having to remove memory boards. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. PHYSICAL_MEMORY is an AUTOGEN parameter. 2 PHYSICALPAGES (VAX only) PHYSICALPAGES sets the maximum number of physical pages of memory to be used on the system. Decreasing this parameter allows you to test smaller configurations of memory without the need to remove memory boards. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. PHYSICALPAGES is an AUTOGEN parameter. 2 PIOPAGES PIOPAGES specifies the size of the process I/O segment, which holds data structures and buffer pool space for RMS to use when it handles I/O that involves process-permanent files. Once PIOPAGES is reset in SYSGEN, any new process receives the changed value. Beginning with OpenVMS Version 7.2, the default value has been raised to 575. The setting has been raised to accommodate the increased demands for process-permanent memory that result from changes made to RMS file-naming parsing in Version 7.2. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. PIOPAGES is an AUTOGEN and DYNAMIC parameter. 2 PIXSCAN PIXSCAN specifies the number of process index slots scanned each second for computable or computable-outswapped processes. These processes receive an automatic priority boost for 1 quantum, unless the priority of the currently executing process is greater than 15. The priority boost is done to avoid potential deadlocks on the system. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. PIXSCAN is an AUTOGEN and DYNAMIC parameter. 2 POOLCHECK This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. POOLCHECK is used to investigate frequent and inexplicable failures in a system. When POOLCHECK is enabled, pool-checking routines execute whenever pool is deallocated or allocated. Two loadable forms of SYSTEM_PRIMITIVES.EXE are available at boot time. The default image, which contains no pool-checking code and no statistics maintenance, is loaded when POOLCHECK is set to zero. When POOLCHECK is set to a nonzero value, the monitoring version of SYSTEM_PRIMITIVES.EXE, which contains both pool-checking code and statistics maintenance, is loaded. Setting the SYSTEM_CHECK parameter to 1 has the effect of setting POOLCHECK to ON (1). For further information about pool checking, refer to the OpenVMS VAX Device Support Manual. POOLCHECK is a DYNAMIC parameter. 2 POOLPAGING POOLPAGING enables (1) paging of pageable dynamic pool. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 POWEROFF POWEROFF enables or disables software requests to the console firmware to remove power from the system. This parameter should normally be turned ON (1) to allow software to make power-off requests. However, POWEROFF can be set to OFF (0) to disable software power-off requests. If firmware or hardware support for the power-off request is not implemented, the shut-down procedure will leave the system halted but fully powered. POWEROFF is a DYNAMIC parameter. 2 PQL_DASTLM PQL_DASTLM sets the default limit on the number of pending ASTs for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DASTLM has the DYNAMIC and GEN attributes. 2 PQL_DBIOLM PQL_DBIOLM sets the default buffered I/O count limit for the number of outstanding buffered I/O operations permitted to a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DBIOLM has the DYNAMIC and GEN attributes. 2 PQL_DBYTLM PQL_DBYTLM sets the default buffered I/O byte count limit for the amount of buffered space available to a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DBYTLM has the DYNAMIC and GEN attributes. 2 PQL_DCPULM PQL_DCPULM sets the default CPU time limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DCPULM specifies the time limit in increments of 10 milliseconds. The default value of 0 imposes no limit on CPU time usage and is typically the correct value for this parameter. PQL_DCPULM has the DYNAMIC and GEN attributes. 2 PQL_DDIOLM PQL_DDIOLM sets the default direct I/O limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DDIOLM has the DYNAMIC and GEN attributes. 2 PQL_DENQLM PQL_DENQLM sets the default enqueue limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DENQLM has the DYNAMIC and GEN attributes. 2 PQL_DFILLM PQL_DFILLM sets the default open file limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DFILLM has the DYNAMIC and GEN attributes. 2 PQL_DJTQUOTA PQL_DJTQUOTA sets the default job table byte count quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DJTQUOTA specifies the number of bytes of paged pool allocated to the job table. The default value is usually adequate, unless a large number of job logical names or temporary mailboxes are used. PQL_DJTQUOTA is a DYNAMIC parameter. 2 PQL_DPGFLQUOTA PQL_DPGFLQUOTA sets the default page file quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). Compaq recommends that this parameter not be smaller than the PQL_DWSEXTENT parameter. PQL_DPGFLQUOTA has the DYNAMIC and GEN attributes. On VAX systems, PQL_DPGFLQUOTA is also an AUTOGEN parameter. 2 PQL_DPRCLM PQL_DPRCLM sets the default subprocess limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DPRCLM has the DYNAMIC and GEN attributes. 2 PQL_DTQELM PQL_DTQELM sets the default number of timer queue entries for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DTQELM has the DYNAMIC and GEN attributes. 2 PQL_DWSDEFAULT PQL_DWSDEFAULT sets the default working set size for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DWSDEFAULT has the AUTOGEN and GEN attributes. 2 PQL_DWSEXTENT PQL_DWSEXTENT sets the default working set extent for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes. 2 PQL_DWSQUOTA PQL_DWSQUOTA sets the default working set quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DWSQUOTA has the AUTOGEN, DYNAMIC, and GEN attributes. 2 PQL_MASTLM PQL_MASTLM sets a default limit on the minimum number of pending ASTs for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MASTLM has the DYNAMIC and GEN attributes. 2 PQL_MBIOLM PQL_MBIOLM sets the minimum buffered I/O limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MBIOLM has the DYNAMIC and GEN attributes. 2 PQL_MBYTLM PQL_MBYTLM sets the minimum buffered I/O byte limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MBYTLM has the DYNAMIC and GEN attributes. 2 PQL_MCPULM PQL_MCPULM sets the minimum CPU time limit in increments of 10 milliseconds for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MCPULM has the DYNAMIC and GEN attributes. 2 PQL_MDIOLM PQL_MDIOLM sets the minimum direct I/O limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MDIOLM has the DYNAMIC and GEN attributes. 2 PQL_MENQLM PQL_MENQLM sets the default limit on the minimum number of locks that can be queued at one time by a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MENQLM has the DYNAMIC and GEN attributes. 2 PQL_MFILLM PQL_MFILLM sets the minimum open file limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MFILLM has the DYNAMIC and GEN attributes. 2 PQL_MJTQUOTA PQL_MJTQUOTA sets the minimum job table byte count quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MJTQUOTA is a DYNAMIC parameter. 2 PQL_MPGFLQUOTA On VAX systems, PQL_MPGFLQUOTA sets the minimum page file quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). Compaq recommends that this parameter be no smaller than PQL_MWSEXTENT. On Alpha systems, PQL_MPGFLQUOTA sets the minimum pagelet file quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MPQFLQUOTA has the DYNAMIC and GEN attributes. On VAX systems, PQL_MPQFLQUOTA is also an AUTOGEN parameter. 2 PQL_MPRCLM PQL_MPRCLM sets the minimum subprocess limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MPRCLM has the DYNAMIC and GEN attributes. 2 PQL_MTQELM PQL_MTQELM sets the minimum number of timer queue entries for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MTQELM has the DYNAMIC and GEN attributes. 2 PQL_MWSDEFAULT PQL_MWSDEFAULT sets the minimum default working set size for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). This value overrides a smaller quantity that is set for a user in AUTHORIZE. PQL_MWSDEFAULT has the AUTOGEN and GEN attributes. 2 PQL_MWSEXTENT PQL_MWSEXTENT sets the minimum working set extent for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). This value overrides a smaller quantity set for a user in AUTHORIZE. PQL_MWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes. 2 PQL_MWSQUOTA PQL_MWSQUOTA sets the minimum working set quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). This value overrides a smaller quantity set for a user in AUTHORIZE. PQL_MWSQUOTA has the AUTOGEN, DYNAMIC, and GEN attributes. 2 PRCPOLINTERVAL PRCPOLINTERVAL specifies, in seconds, the polling interval used to look for Systems Communications Services (SCS) applications, such as the connection manager and mass storage control protocol disks, on other nodes. All discovered nodes are polled during each interval. This parameter trades polling overhead against quick recognition of new systems or servers as they appear. PRCPOLINTERVAL is a DYNAMIC parameter. On Alpha systems, PRCPOLINTERVAL is also an AUTOGEN parameter. 2 PRIORITY_OFFSET PRIORITY_OFFSET specifies the difference in priority required by the scheduler for one process to preempt the current process. A value of 2, for example, means that if the current process is executing at priority 1, a computable process at priority 2 or 3 is not allowed to preempt the current process. However, a priority 4 or higher process can preempt the current process. This mechanism affects only normal priority (0-15) processes. The default value is 0. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 PROCSECTCNT PROCSECTCNT sets the number of section descriptors that a process can contain. Each section descriptor increases the fixed portion of the process header by 32 bytes. Set a value greater than the maximum number of image sections in any section to be run, as indicated by the linkage memory allocation map for the image. PROCSECTCNT has the AUTOGEN and GEN attributes. 2 PSEUDOLOA (VAX only) PSEUDOLOA specifies (in pages) the size of the PDA0 system image. PSEUDOLOA is used to boot standalone BACKUP from magnetic tape. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 PU_OPTIONS PU_OPTIONS is reserved for Compaq use only. 2 QBUS_MULT_INTR (VAX only) QBUS_MULT_INTR enables (1) multilevel interrupt dispatching on systems that use the Q22-bus adapter. Refer to the OpenVMS VAX Device Support Manual for more information about the QBUS_MULT_INTR system parameter. (This manual has been archived but is available on the OpenVMS Documentation CD-ROM.) This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 QDSKINTERVAL QDSKINTERVAL establishes, in seconds, the disk quorum polling interval. The default value is 3. 2 QDSKVOTES QDSKVOTES specifies the number of votes contributed by a quorum disk in a cluster. 2 QUANTUM QUANTUM defines the following: o Processor time: maximum amount of processor time a process can receive before control passes to another process of equal priority that is ready to compute o Balance set residency: minimum amount of service a compute- state process must receive before being swapped out to secondary storage QUANTUM has the DYNAMIC and MAJOR attributes. On Alpha systems, QUANTUM also has the AUTOGEN attribute. 2 RAD_SUPPORT (Alpha only) RAD_SUPPORT enables RAD-aware code to be executed on systems that support Resource Affinity Domains (RADs); for example, AlphaServer GS160 systems. A RAD is a set of hardware components (CPUs, memory, and I/O) with common access characteristics. For more information about using OpenVMS RAD features, see the OpenVMS Alpha Galaxy and Partitioning Guide. RAD_SUPPORT has the GEN attribute. 2 REALTIME_SPTS (VAX only) REALTIME_SPTS reserves a number of system page table entries for mapping connect-to-interrupt processes into system space. This value should normally remain at the default (0) in an environment that is not real-time. Where connect-to-interrupt processes do use the system, this value should represent the maximum number of pages that all concurrent connect-to-interrupt processes must map into system space. See the OpenVMS VAX Device Support Manual REALTIME_SPTS has the DYNAMIC, GEN, and MAJOR attributes. 2 RECNXINTERVAL RECNXINTERVAL establishes the polling interval, in seconds, during which to attempt reconnection to a remote system. RECNXINTERVAL is a DYNAMIC parameter. On Alpha systems, RECNXINTERVAL is also an AUTOGEN parameter. 2 RESALLOC RESALLOC controls whether resource allocation checking is performed. The default value of 0 disables resource allocation checking. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 RESHASHTBL RESHASHTBL defines the number of entries in the lock management resource name hash table. Each entry requires 4 bytes. A typical tuning goal is to have the RESHASHTBL parameter about four times larger than the total number of resources in use on the system. Managers of systems with memory constraints or systems that are not critically dependent on locking speed could set the table to a smaller size. RESHASHTBL has the AUTOGEN, FEEDBACK, and MAJOR attributes. 2 RJOBLIM RJOBLIM defines the maximum number of remote terminals allowed in the system at any one time. RJOBLIM is a DYNAMIC parameter. 2 RMS_DFMBC RMS_DFMBC specifies a default multiblock count only for record I/O operations, where count is the number of blocks to be allocated for each I/O buffer. You can set this system parameter with the DCL command SET RMS_ DEFAULT/SYSTEM and display the parameter with the SHOW RMS_ DEFAULT command. RMS_DFMBC is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFIDX RMS_DFMBFIDX establishes the default RMS multibuffer count for indexed sequential disk operations. This value defines the number of I/O buffers that RMS allocates for each indexed file. For sequential access, a larger number that allows some of the index buckets to remain in memory can improve performance. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFIDX is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFREL RMS_DFMBFREL establishes the default RMS multibuffer count for relative disk operations. This value defines the number of I/O buffers that RMS allocates for each relative file. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFREL is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFSDK RMS_DFMBFSDK establishes the default RMS multibuffer count for sequential disk operations. This value defines the number of I/O buffers that RMS allocates for sequential disk files. The default value is usually adequate. However, if read-ahead or write-behind operations are used, a larger number improves performance. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFSDK is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFSMT RMS_DFMBFSMT establishes the default RMS multibuffer count for magnetic tape operations. This value defines the number of I/O buffers that RMS allocates for magnetic tape files. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFSMT is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFSUR RMS_DFMBFSUR establishes the default multibuffer count for unit record devices. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFSUR is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFNBC RMS_DFNBC specifies a default block count for network access to remote, sequential, indexed sequential, and relative files. The network block count value represents the number of blocks that RMS is prepared to allocate for the I/O buffers used to transmit and receive data. The buffer size used for remote file access, however, is the result of a negotiation between RMS and the remote file access listener (FAL). The buffer size chosen is the smaller of the two sizes presented. Thus, RMS_DFNBC places an upper limit on the network buffer size that is used. It also places an upper limit on the largest record that can be transferred to or from a remote file. In other words, the largest record that can be transferred must be less than or equal to RMS_DFNBC multiplied by 512 bytes. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFNBC is an AUTOGEN and DYNAMIC parameter. 2 RMS_EXTEND_SIZE RMS_EXTEND_SIZE specifies the number of blocks by which files are extended as they are written. This number should be chosen to balance the amount of extra disk space wasted at the ends of each file against the performance improvement provided by making large extents infrequently. When small disk quotas are used, specify a small number such as the disk cluster size to prevent the user's disk quota from being consumed. If the value of 0 is used, RMS allocates large extents and truncates the file back to its actual usage when it closes. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_EXTEND_SIZE is a DYNAMIC parameter. 2 RMS_FILEPROT RMS_FILEPROT determines the default file protection for system processes such as those that create the error log, operator log, and job controller. It also determines default file protection for processes created by the job controller (all interactive and batch processes). Because a process always inherits its default file protection from its creator process, RMS_FILEPROT determines default file protection only for users who do not execute the DCL command SET PROTECTION/DEFAULT in their login command procedures or during interactive sessions. The protection is expressed as a mask. (See the discussion of the $CRMPSC system service in the OpenVMS System Services Reference Manual for more information about specifying protection masks.) By default, the mask is 64000 (decimal) or FA00 (hexadecimal), which represents the following protection: (S:RWED,O:RWED,G:RE,W:) You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. 2 RMS_PROLOGUE RMS_PROLOGUE specifies the default prologue RMS uses to create indexed files. The default value 0 specifies that RMS should determine the prologue based on characteristics of the file. A value of 2 specifies Prologue 2 or Prologue 1, and 3 specifies Prologue 3. The RMS prologues are described in the OpenVMS Record Management Services Reference Manual. RMS_PROLOGUE is a DYNAMIC parameter. 2 RSRVPAGCNT RSRVPAGCNT sets the number of pages that are reserved and escrowed for the current process page file. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 S0_PAGING S0_PAGING controls paging of system code: o Setting bit 0 disables paging of all Exec code and data. o Setting bit 1 disables paging of all RMS code and data. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 S2_SIZE (Alpha only) S2_SIZE is the number of megabytes to reserve for S2 space. This value does not include the size required for Extended File Cache (XFC). 2 SA_APP SA_APP is a special parameter reserved for Compaq use only. 2 SAVEDUMP If the dump file is saved in the page file, SAVEDUMP specifies whether the page file is saved until the dump file is analyzed. The default value 0 specifies that the page file should not be retained. A value of 1 specifies that the dump written to the page file should be retained until either copied or released using the SDA utility. 2 SBIERRENABLE (VAX only) This parameter enables (1) SBI error detection and logging. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 SCH_CTLFLAGS (VAX only) This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. The vector scheduling subsystem presently provides an enlarged quantum to processes requiring vector capability. Customer sites can disable vector quantum adjustment by setting bit NO_VEC_ QUANTADJ (bit 9) in the system parameter SCH_CTLFLAGS. Setting this bit causes the scheduler to treat the vector processes and scalar processes uniformly. However, doing so results in more frequent vector context switches when the number of vector processes exceeds the number of vector processors in the system. SCH_CTLFLAGS is a DYNAMIC parameter. 2 SCSBUFFCNT On VAX systems, SCSBUFFCNT is the number of buffer descriptors configured for all SCA. If an SCA device is not configured on your system, this parameter is ignored. Generally speaking, each data transfer needs a buffer descriptor and thus the number of buffer descriptors can be a limit on the number of possible simultaneous I/Os. Various performance monitors report when a system is out of buffer descriptors for a given workload which is an indication that a larger value for SCSBUFFCNT is worth considering. Note that AUTOGEN provides feedback for this parameter on VAX systems only. On Alpha systems, the SCS buffers are allocated as needed, and SCSBUFFCNT is reserved for Compaq use only. SCSBUFFCNT has the AUTOGEN, FEEDBACK, and GEN attributes. 2 SCSCONNCNT Beginning with OpenVMS Version 7.2, this parameter is obsolete. SCS connections are now allocated and expanded only as needed, up to a limit of 65,000. 2 SCSFLOWCUSH Specifies the lower limit for receive buffers at which point SCS starts to notify the remote SCS of new receive buffers. For each connection, SCS tracks the number of receive buffers available. SCS communicates this number to the SCS at the remote end of the connection. However, SCS does not need to do this for each new receive buffer added. Instead, SCS notifies the remote SCS of new receive buffers if the number of receive buffers falls as low as the SCSFLOWCUSH value. The default value is adequate on most systems. If an SCA port is not configured on your system, this parameter is ignored. SCSFLOWCUSH is a DYNAMIC parameter. 2 SCSI_NOAUTO (VAX only) This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. SCSI_NOAUTO prevents the loading of a disk or tape SCSI class driver for any given device ID in a configuration that includes a SCSI third-party device. The SCSI_NOAUTO system parameter stores a bit mask of 32 bits, where the low-order byte corresponds to the first SCSI bus (PKA0), the second byte corresponds to the second SCSI bus (PKB0), and so on, as follows: #31 24 23 16 15 8 7 0 +-------+-------+-------+-------+ | D | C | B | A | +-------+-------+-------+-------+ For each SCSI bus, setting the low-order bit inhibits automatic configuration of the device with SCSI device ID 0; setting the second low-order bit inhibits automatic configuration of the device with SCSI device ID 1, and so forth. For instance, the value 00002000 subscript 16 prevents the device with SCSI ID 5 on the bus identified by SCSI port ID B from being configured. By default, all the bits in the mask are cleared, allowing all devices to be configured. SCSI_NOAUTO is a DYNAMIC parameter. 2 SCSICLUSTER_P[1-4] (Alpha only) SCSICLUSTER_P[1-4] parameters allow non-Compaq peripherals (CPU-lookalikes) in SCSI clusters. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 SCSMAXDG This parameter is reserved for Compaq use only. SCSMAXDG has the GEN attribute. 2 SCSMAXMSG This parameter is reserved for Compaq use only. SCSMAXMSG has the GEN attribute. 2 SCSNODE SCSNODE specifies the name of the computer. This parameter is not dynamic. Specify SCSNODE as a string of up to six characters. Enclose the string in quotation marks. If the computer is in an OpenVMS Cluster, specify a value that is unique within the cluster. Do not specify the null string. If the computer is running DECnet for OpenVMS, the value must be the same as the DECnet node name. SCSNODE has the AUTOGEN and GEN attributes. 2 SCSRESPCNT SCSRESPCNT is the total number of response descriptor table entries (RDTEs) configured for use by all system applications. If SCA or DSA ports are not configured on your system, the system ignores SCSRESPCNT. SCSRESPCNT has the AUTOGEN, FEEDBACK, and GEN attributes. 2 SCSSYSTEMID Specifies a number that identifies the computer. This parameter is not dynamic. SCSSYSTEMID is the low-order 32 bits of the 48- bit system identification number. If the computer is in an OpenVMS Cluster, specify a value that is unique within the cluster. Do not use zero as the value. If the computer is running DECnet for OpenVMS, calculate the value from the DECnet address using the following formula: SCSSYSTEMID = ((DECnet area number) * 1024) + (DECnet node number) Example: If the DECnet address is 2.211, calculate the value as follows: SCSSYSTEMID = (2 * 1024) + 211 = 2259 SCSSYSTEMID has the GEN attribute. 2 SCSSYSTEMIDH Specifies the high-order 16 bits of the 48-bit system identification number. This parameter must be set to 0. It is reserved by Compaq for future use. SCSSYSTEMIDH has the GEN attribute. 2 SECURITY_POLICY SECURITY_POLICY allows a system to run in a C2 or B1 configuration and to subset out particular pieces of functionality-to exclude functionality that is outside the evaluated configuration or to preserve compatibility with previous versions of the operating system. See the OpenVMS Guide to System Security for further information about the C2 and B1 evaluated configurations. The following bits are defined: Bit Description 0 Allows DECwindows to display PostScript extensions 1 Allows multiple user names to connect to DECW$SERVER 2 Allows unevaluated DECwindows transports (such as TCP/IP) 3 Allows $SIGPRC and $PRCTERM to span job trees 4 Allows security profile changes to protected objects on a local node when the object server is absent and cannot update the cluster database VMS$OBJECTS.DAT 5 Allows creation of protected objects on a local node when the object server is absent and cannot update the cluster database VMS$OBJECTS.DAT 6 Allows SPAWN or LIB$SPAWN commands in CAPTIVE accounts 7 Allows intrusions on a clusterwide or local basis (If the bit is cleared, intrusions are clusterwide.) The default value of 7 preserves compatibility with existing DECwindows Motif behavior. A value of 0 disables all unevaluated configurations. 2 SETTIME SETTIME enables (1) or disables (0) solicitation of the time of day each time the system is booted. This parameter should usually be off (0), so that the system sets the time of day at boot time to the value of the processor time-of-day register. You can reset the time after the system is up with the DCL command SET TIME (see the OpenVMS DCL Dictionary). 2 SHADOWING SHADOWING enables or disables shadowing and specifies the mode of shadowing operations that you want to enable. SHADOWING is a value that specifies the type of disk class driver that is loaded on the system: DUDRIVER, DSDRIVER, or SHDRIVER. See Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing. Specify one of the following values: Value Description 0 No shadowing is enabled; SHDRIVER is not loaded. This is the default value. 2 Phase II shadowing enabled. SHDRIVER is loaded. Phase II shadowing provides shadowing of all disks located on a standalone system or an OpenVMS Cluster system. Note that a parameter value of 1 represents Phase I, which is no longer supported. Instead, use Phase II shadowing. 2 SHADOW_MAX_COPY Use this parameter for Phase II shadowing only. The value of SHADOW_MAX_COPY controls how many parallel copy threads are allowed on a given node. Carefully consider the needs of each shadowed VAX node when you set this parameter. Too high a value for SHADOW_MAX_COPY can affect performance by allowing too many copy threads to operate in parallel. Too low a value unnecessarily restricts the number of threads your system can effectively handle. See Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing. SHADOW_MAX_COPY has the AUTOGEN and DYNAMIC attributes. 2 SHADOW_MAX_UNIT SHADOW_MAX_UNIT specifies the maximum number of shadow sets that can exist on a node. The setting must be equal to or greater than the number of shadow sets you plan to have on a system. Dismounted shadow sets, unused shadow sets, and shadow sets with no write bitmaps allocated to them are included in the total. NOTE Review this default carefully. The setting must be equal to or greater than the number of shadow sets you plan to have on a system. If you attempt to mount more shadow sets than the number specified by SHADOW_MAX_UNIT, the MOUNT command will fail. Dismounted shadow sets, unused shadow sets, and shadow sets with no write bitmaps allocated to them are included in the count for SHADOW_MAX_UNIT. This system parameter is not dynamic; that is, a reboot is required when you change the setting. The default setting on OpenVMS Alpha systems is 500; on OpenVMS VAX systems, the default is 100. The minimum value is 10, and the maximum value is 10,000. 2 SHADOW_MBR_TMO SHADOW_MBR_TMO controls the amount of time the system tries to fail over physical members of a shadow set before removing them from the set. The SHADOW_MBR_TMO parameter replaces the temporary VMSD3 parameter used in prior releases. The SHADOW_MBR_TMO parameter is valid for use only with Phase II of Volume Shadowing for OpenVMS. You cannot set this parameter for use with Phase I, which is obsolete. Use the SHADOW_MBR_TMO parameter (a word) to specify the number of seconds, in decimal from 1 to 65,535, during which recovery of a repairable shadow set is attempted. If you do not specify a value or if you specify 0, the default delay of 120 seconds is used. Because SHADOW_MBR_TMO is a dynamic parameter, you should use the SYSGEN command WRITE CURRENT to permanently change its value. SHADOW_MBR_TWO is a DYNAMIC parameter. 2 SHADOW_REMOVE_1 (Alpha only) SHADOW_REMOVE_1 is reserved for Compaq use only. 2 SHADOW_REMOVE_2 (Alpha only) SHADOW_REMOVE_2 is reserved for Compaq use only. 2 SHADOW_SYS_DISK A SHADOW_SYS_DISK parameter value of 1 enables shadowing of the system disk. A value of 0 disables shadowing of the system disk. The default value is 0. Also specify a system disk shadow set virtual unit number with the SHADOW_SYS_UNIT system parameter, unless the desired system disk unit number is DSA0. To enable minimerge on a system disk, add the value 4096 to your existing SHADOW_SYS_DISK value. For example, if you have SHADOW_SYS_DISK set to a value of 1, change it to 4097 to enable minimerge. Also, be sure to set the DUMPSTYLE parameter to dump off system disk, as described in the OpenVMS System Manager's Manual. 2 SHADOW_SYS_TMO The SHADOW_SYS_TMO parameter has the following two distinct uses: o At system boot time, when this is the first node in the cluster to boot and to create this specific shadow set. If the proposed shadow set is not currently mounted in the cluster, use this parameter to extend the time a booting system waits for all former members of the shadowed system disk to become available. o Once the system successfully mounts the virtual unit and begins normal operations. In this usage, the SHADOW_SYS_ TMO parameter controls the time the operating system waits for errant members of a system disk. (Use the SHADOW_MBR_TMO parameter to control the time the operating system waits for the errant members of an application disk.) This parameter applies only to members of the system disk shadow set. All nodes using a particular system disk shadow set should have their SHADOW_SYS_TMO parameter set to the same value once normal operations begin. The default value is 120 seconds. Change this parameter to a higher value if you want the system to wait more than the 120- second default for all members to join the shadow set. You can set the parameter value to 120 through 65,535 seconds. 2 SHADOW_SYS_UNIT Use this parameter for Phase II shadowing only. The SHADOW_SYS_ UNIT parameter is an integer value that contains the virtual unit number of the system disk. The default value is 0. The maximum value allowed is 9999. This parameter is effective only when the SHADOW_SYS_DISK parameter has a value of 1. This parameter should be set to the same value on all nodes booting off a particular system disk shadow set. See Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing. 2 SHADOW_SYS_WAIT The SHADOW_SYS_WAIT parameter extends the time a booting system waits for all current members of a mounted shadowed system disk to become available to this node. The shadow set must already be mounted by at least one other cluster node for this parameter to take effect. The default value is 480 seconds. Change this parameter to a higher value if you want the system to wait more than the 480- second default for all members to join the shadow set. You can set the parameter value to 1 through 65,535 seconds. 2 SMCI_FLAGS (Alpha Galaxy platforms only) The SMCI_FLAGS parameter controls operational aspects of SYS$PBDRIVER, the Galaxy Shared Memory Cluster Interconnect (SMCI). Bits in the bit mask are the following: Bit Mask Description 0 0 0 = Do not create local communications channels (SYSGEN default). Local SCS communications are primarily used in test situations and are not needed for normal operations. Not creating local communications saves resources and overhead. 1 = Create local communications channels. 1 2 0 = Load SYS$PBDRIVER if booting into both a Galaxy and a Cluster (SYSGEN Default). 1 = Load SYS$PBDRIVER if booting into a Galaxy. 2 4 0 = Minimal console output (SYSGEN default). 1 = Full console output; SYS$PBDRIVER displays console messages when it creates and tears down communications channels. SMCI_FLAGS has the DYNAMIC attribute. 2 SMCI_PORTS (Alpha Galaxy platforms only) The Shared Memory Cluster Interconnect (SMCI) system parameter SMCI_PORTS controls initial loading of SYS$PBDRIVER. This parameter is a bit mask; bits 0 through 25 each represent a controller letter. If bit 0 is set, which is the default setting, PBAx is loaded (where x represents the Galaxy Partition ID). If bit 1 is set, PBBx is loaded, and so on up to bit 25, which causes PBZx to be loaded. For OpenVMS Alpha Version 7.2, Compaq recommends leaving this parameter at the default value of 1. Loading additional ports allows multiple paths between Galaxy instances. In the initial release of the Galaxy software, having multiple communications channels is not an advantage because SYS$PBDRIVER does not support fast path. A future release of OpenVMS will provide Fast Path support for SYS$PBDRIVER, when multiple CPUs improve throughput by providing multiple communications channels between instances. 2 SMP_CPUS SMP_CPUS identifies which secondary processors, if available, are to be booted into the multiprocessing system at boot time. SMP_CPUS is a 32-bit mask; if the value of a bit in the mask is 1, the processor with the corresponding CPU ID is booted into the multiprocessing system (if it is available). For example, if you want to boot only the CPUs with CPU IDs 0 and 1, specify the value 3 (both bits are on). The default value of SMP_CPUS, -1, boots all available CPUs into the multiprocessing system. Note that although a bit in the mask corresponds to the primary processor's CPU ID, the primary processor is always booted. That is, if the mask is set to 0, the primary CPU still boots. Any available secondary processors are not booted into the multiprocessing system. This parameter is ignored if the MULTIPROCESSING parameter is set to 0. 2 SMP_CPUSH SMP_CPUSH is a special parameter reserved for Compaq use only. Compaq recommends that you use the default value. 2 SMP_LNGSPINWAIT Certain shared resources in a multiprocessing system take longer to become available than allowed by the SMP_SPINWAIT parameter. SMP_LNGSPINWAIT establishes, in 10-microsecond intervals, the length of time a processor in a multiprocessing system waits for these resources. A timeout causes a CPUSPINWAIT bugcheck. The default value is 3000000 (3 million 10-microsecond intervals or 30 seconds). 2 SMP_SANITY_CNT SMP_SANITY_CNT establishes, in 10-millisecond intervals, the timeout period for each CPU in a symmetric multiprocessing (SMP) system. Each CPU in an SMP system monitors the sanity timer of one other CPU in the configuration to detect hardware or software failures. If allowed to go undetected, these failures could cause the cluster to hang. A timeout causes a CPUSANITY bugcheck. The default value is 300 milliseconds (30 10-millisecond intervals). 2 SMP_SPINWAIT SMP_SPINWAIT establishes, in 10-microsecond intervals, the amount of time a CPU in an SMP system normally waits for access to a shared resource. This process is called spinwaiting. A timeout causes a CPUSPINWAIT bugcheck. The default value is 100000 (100,000 10-microsecond intervals or 1 second). 2 SMP_TICK_CNT SMP_TICK_CNT sets the frequency of sanity timer checks by each CPU in a multiprocessing system. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 SPTREQ (VAX only) SPTREQ sets the number of system page table (SPT) entries required for mapping the following components: Executive image RMS image SYSMSG.EXE file Multiport memory structures Each MASSBUS adapter Each UNIBUS adapter Each DR32 adapter The number of system page table entries required for all other purposes is automatically computed and added to the value of SPTREQ to yield the actual size of the system page table. SPTREQ is an AUTOGEN parameter. 2 SSINHIBIT SSINHIBIT controls whether system services are inhibited (1) (on a per-process basis). By default, system services are not inhibited (0). This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 STARTUP_P1-8 STARTUP_P1 specifies the type of system boot the system- independent startup procedure is to perform. If STARTUP_P1 is " ", a full boot is performed; "MIN" indicates a minimum boot that starts only what is absolutely necessary for the operating system to run. STARTUP_P2 controls whether verification is set during the execution of the system-independent startup procedure. If STARTUP_P2 is " ", verification is not enabled; "TRUE" indicates that verification is enabled. Beginning in OpenVMS Version 7.2, if STARTUP_P3 is set to AGEN, the system executes AUTOGEN at the end of the startup sequence. STARTUP_P4 through STARTUP_P8 are reserved for future use. 2 SWP_PRIO SWP_PRIO sets the priority of I/O transfers initiated by the swapper. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 SWPALLOCINC (VAX only) SWPALLOCINC sets the size (in blocks) to use to back up swap file space allocation in the swap or page file. Space in the file is allocated in multiples of this unit (up to WSQUOTA) to guarantee swap space. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 SWPFAIL SWPFAIL sets the number of consecutive swap failures allowed before the swap schedule algorithm is changed to ignore the swap quantum protection. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 SWPFILCNT On VAX systems, SWPFILCNT defines the maximum number of swap files that can be installed. On Alpha systems, beginning in OpenVMS Version 7.3, this parameter is obsolete. 2 SWPOUTPGCNT This parameter allows the swapper an alternative mechanism before actually performing swaps. On VAX systems, SWPOUTPGCNT defines the minimum number of pages to which the swapper should attempt to reduce a process before swapping it out. The pages taken from the process are placed into the free-page list. On Alpha systems, SWPOUTPGCNT defines the minimum number of pagelets to which the swapper should attempt to reduce a process before swapping it out. The pagelets taken from the process are placed into the free-page list. SWPOUTPGCNT has the DYNAMIC attribute. On VAX systems, SWPOUTPGCNT also has the AUTOGEN attribute. 2 SWPRATE SWPRATE sets the swapping rate (in 10-millisecond units). This parameter limits the amount of disk bandwidth consumed by swapping. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 SYSMWCNT SYSMWCNT sets the quota for the size of the system working set, which contains the pageable portions of the system, the paged dynamic pool, RMS, and the resident portion of the system message file. While a high value takes space away from user working sets, a low value can seriously impair system performance. Appropriate values vary, depending on the level of system use. When the system is running at full load, check the rate of system faults with the MONITOR PAGE command of the Monitor utility. An average system page fault rate of between 0 and 3 page faults per second is desirable. If the system page fault rate is high, and especially if the system seems to be slow, you should increase the value of SYSMWCNT. However, do not set this parameter so high that system page faulting never occurs. SYSMWCNT has the AUTOGEN, GEN, and MAJOR attributes. 2 SYSPFC SYSPFC sets the number of pages to be read from disk on each system paging operation. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 SYSTEM_CHECK SYSTEM_CHECK investigates intermittent system failures by enabling a number of run-time consistency checks on system operation and recording some trace information. Enabling SYSTEM_CHECK causes the system to behave as if the following system parameter values are set (although the values of the following parameters are not actually changed): Parameter Value Description BUGCHECKFATAL 1 Crash the system on nonfatal bugchecks. POOLCHECK %X616400FF Enable all poolchecking, with an allocated pool pattern of %x61616161 ('aaaa') and deallocated pool pattern of x64646464 ('dddd'). MULTIPROCESSING 2 Enable full synchronization checking. While SYSTEM_CHECK is enabled, the previous settings of the BUGCHECKFATAL and MULTIPROCESSING parameters are ignored. However, setting the parameter POOLCHECK to a nonzero value overrides the setting imposed by SYSTEM_CHECK. Setting SYSTEM_CHECK creates certain image files that are capable of the additional system monitoring. These image files are located in SYS$LOADABLE_IMAGES and can be identified by the suffix _MON. For information about the type of data checking performed by SYSTEM_CHECK, see the description of the ACP_DATACHECK parameter. For information about the performance implications of enabling SYSTEM_CHECK, see OpenVMS Performance Management. On VAX systems, SYSTEM_CHECK is a special parameter, which is subject to change at any time and should be modified only if recommended by Compaq. 2 TAILORED TAILORED specifies whether or not the system is tailored during installation. Compaq recommends that you use the default value. 2 TAPE_ALLOCLASS TAPE_ALLOCLASS determines the tape allocation class for the system. The tape allocation class creates a unique clusterwide device name for multiple access paths to the same tape. The TAPE_ALLOCLASS parameter can also be used to generate a unique clusterwide name for tape devices with identical unit numbers. 2 TAPE_MVTIMEOUT TAPE_MVTIMEOUT is the time in seconds that a mount verification attempt continues on a given magnetic tape volume. If the mount verification does not recover the volume within that time, the I/O operations outstanding to the volume terminate abnormally. TAPE_MVTIMEOUT is a DYNAMIC parameter. 2 TBSKIPWSL TBSKIPWSL specifies the maximum number of working set list entries that may be skipped while scanning for a "good" entry to discard. Setting this parameter to 0 disables skipping. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 TIME_CONTROL This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. TIME_CONTROL is an SMP bit mask parameter that controls debugging functions. The following bits are defined: Bit Description 0 Obsolete. 1 (EXE$V_SANITY) Disables the SMP sanity timer support. 2 (EXE$V_NOSPINWAIT) Disables the functional behavior of the SMP spinwait support. TIME_CONTROL is a DYNAMIC parameter. 2 TIMEPROMPTWAIT TIMEPROMPTWAIT defines the number of seconds that you want a processor to wait for the time and date to be entered when a system boot occurs, if the processor's time-of-year clock does not contain a valid time. (The time unit of micro-fortnights is approximated as seconds in the implementation.) If the time specified by TIMEPROMPTWAIT elapses, the system continues the boot operation, and the date and time are set to the last recorded time that the system booted. NOTE Compaq recommends that you set the correct system time before allowing the system to run, so that all functions using time-stamping (such as the operator log, the error log, accounting records, file creation dates, and file expiration dates) contain correct time values. Depending on the value specified for the TIMEPROMPTWAIT parameter, the system acts in one of the following ways: o If TIMEPROMPTWAIT is 0, no prompt or wait occurs; the system boots immediately, using the time of the last boot as the system time. o If TIMEPROMPTWAIT is a positive number less than 32768, one prompt is issued and the value dictates how many seconds you can take to respond with a time. If you do not provide a time before TIMEPROMPTWAIT elapses, the system boots, using the time of the last boot as the system time. o If TIMEPROMPTWAIT is a number in the range of 32768 through 65535, the prompt for the time is issued at intervals starting with 2 and doubling until 256 seconds is reached. If no response is received, the prompts restart, with the 2-second interval. This prompting process repeats indefinitely, until you specify a time. 2 TIMVCFAIL TIMVCFAIL specifies the time required for an adapter or virtual circuit failure to be detected. Compaq recommends that the default value be used. Compaq also recommends that this value be lowered only in OpenVMS Cluster of three CPUs or less, that the same value be used on each computer in the cluster, and that dedicated LAN segments be used for cluster I/O. TIMVCFAIL is a DYNAMIC parameter. 2 TMSCP_LOAD TMSCP_LOAD allows the loading of the tape mass storage control protocol server software. The TMSCP_LOAD parameter also sets locally connected tapes served. Refer to OpenVMS Cluster Systems for information about setting the TMSCP_LOAD parameter. Setting TMSCP_LOAD to 0 inhibits the loading of the tape server and the serving of local tapes. Setting TMSCP to 1 loads the tape server into memory at the time the system is booted and makes all directly connected tape drives available clusterwide. The following table describes the two states of the TMSCP_LOAD parameter: State Function 0 Do not load the TMSCP tape server. Do not serve any local tape devices clusterwide. This is the default value. 1 Load the TMSCP tape server. Serve all local TMSCP tape devices clusterwide. TMSCP_LOAD is an AUTOGEN parameter. 2 TMSCP_SERVE_ALL TMSCP_SERVE_ALL is a bit mask that controls the serving of tapes. The settings take effect when the system boots. You cannot change the settings when the system is running. Starting with OpenVMS Version 7.2, the serving types are implemented as a bit mask. To specify the type of serving your system will perform, locate the type you want in the following table and specify its value. For some systems, you may want to specify two serving types, such as serving all tapes except those whose allocation class does not match. To specify such a combination, add the values of each type, and specify the sum. In a mixed-version cluster that includes any systems running OpenVMS Version 7.1-x or earlier, serving all available tapes is restricted to serving all tapes except those whose allocation class does not match the system's allocation class (pre-Version 7.2 meaning). To specify this type of serving, use the value 9, which sets bit 0 and bit 3. The following table describes the serving type controlled by each bit and its decimal value. Value When Bit Set Description Bit 0 1 Serve all available tapes (locally attached and those connected to HSx and DSSI controllers). Tapes with allocation classes that differ from the system's allocation class (set by the ALLOCLASS parameter) are also served if bit 3 is not set. Bit 1 2 Serve locally attached (non-HSx and non-DSSI) tapes. Bit 2 N/A Reserved. Bit 3 8 Restrict the serving specified by bit 0. All tapes except those with allocation classes that differ from the system's allocation class (set by the ALLOCLASS parameter) are served. This is pre-Version 7.2 behavior. If your cluster includes systems running OpenVMS Version 7.1-x or earlier, and you want to serve all available tapes, you must specify 9, the result of setting this bit and bit 0. Although the serving types are now implemented as a bit mask, the values of 0, 1, and 2, specified by bit 0 and bit 1, retain their original meanings: o 0 - Do not serve any tapes (the default for earlier versions of OpenVMS). o 1 - Serve all available tapes. o 2 - Serve only locally attached (non-HSx and non-DSSI) tapes. If the TMSCP_LOAD system parameter is 0, TMSCP_SERVE_ALL is ignored. 2 TTY_ALTALARM TTY_ALTALARM sets the size of the alternate type-ahead buffer alarm. This value indicates at what point an XOFF should be sent to terminals that use the alternate type-ahead buffers with the size specified by the TTY_ALTYPAHD parameter. 2 TTY_ALTYPAHD TTY_ALTYPAHD sets the size of the alternate type-ahead buffer. Use this parameter to allow the block mode terminals and communications lines to operate more efficiently. The default value is usually adequate. Do not exceed the maximum value of 32767 when setting this parameter. 2 TTY_AUTOCHAR TTY_AUTOCHAR sets the character the terminal driver echoes when the job controller has been notified. TTY_AUTOCHAR is a DYNAMIC parameter. 2 TTY_BUF TTY_BUF sets the default line width for terminals. 2 TTY_CLASSNAME TTY_CLASSNAME provides the 2-character prefix for the terminal class driver name that is required when booting. Changing the prefix can be useful when debugging a new terminal driver. 2 TTY_DEFCHAR TTY_DEFCHAR sets the default characteristics for terminals, using a code derived by summing the following hexadecimal values: Characteristic Value (Hex) Function PASSALL 1 Passall. NOECHO 2 Noecho mode. NOTYPEAHEAD 4 No type-ahead buffer. ESCAPE 8 Escape sequence processing. HOSTSYNC 10 Host can send XON and XOFF. TTSYNC 20 Terminal can send XON and XOFF. SCRIPT 40 Internal use only. LOWER 80 Lowercase. MECHTAB 100 Mechanical tabs. WRAP 200 Wraparound at end of line. CRFILL 400 Perform carriage return fill. LFFILL 800 Perform line feed fill. SCOPE 1000 Terminal is a scope. REMOTE 2000 Internal use only. EIGHTBIT 8000 Eight-bit terminal. MBXDSABL 10000 Disable mailbox. NOBRDCST 20000 Prohibit broadcast. READSYNC 40000 XON and XOFF on reads. MECHFORM 80000 Mechanical form feeds. HALFDUP 100000 Set for half-duplex operation. MODEM 200000 Set for modem signals. PAGE FF000000 Page size. Default is 24. Do not set the CRFILL or LRFILL characteristic as the default in TTY_DEFCHAR. Where a condition is false, the value is 0. The upper byte is the page length. The default characteristics are 24 lines per page, terminal synchronization, wraparound, lowercase, scope, and full-duplex. 2 TTY_DEFCHAR2 TTY_DEFCHAR2 sets a second longword of default terminal characteristics. The default characteristics are represented as a code that is derived by summing the following hexadecimal values: Characteristic Value (Hex) Function LOCALECHO 1 Enable local echo terminal logic; use with the TTY_DEFCHAR NOECHO characteristic. AUTOBAUD 2 Enable autobaud detection. HANGUP 4 Hang up on logout. MODHANGUP 8 Allow modification of HANGUP without privileges. BRDCSTMBX 10 Allow sending of broadcasts to mailboxes. XON 20 (No effect in this parameter.) DMA 40 (No effect in this parameter.) ALTYPEAHD 80 Use the alternate type-ahead parameters. SETSPEED 100 Clear to allow setting of speed without privileges. DCL_MAILBX 200 Function reserved for Compaq use only. DECCRT4 400 Terminal is DIGITAL CRT Level 4. COMMSYNC 800 Enable flow control using modem signals. EDITING 1000 Line editing allowed. INSERT 2000 Sets default mode for insert. FALLBACK 4000 Do not set this bit with SYSGEN. Refer to the OpenVMS Terminal Fallback Utility Manual for information about setting the FALLBACK terminal characteristic using the Terminal Fallback utility. (This manual has been archived but is available on the OpenVMS Documentation CD-ROM.) DIALUP 8000 Terminal is a dialup line. SECURE 10000 Guarantees that no process is connected to terminal after Break key is pressed. DISCONNECT 20000 Allows terminal disconnect when a hangup occurs. PASTHRU 40000 Terminal is in PASTHRU mode. SYSPWD 80000 Log in with system password only. SIXEL 100000 Sixel graphics. DRCS 200000 Terminal supports loadable character fonts. PRINTER 400000 Terminal has printer port. APP_KEYPAD 800000 Notifies application programs of state to set keypad on exit. ANSICRT 1000000 Terminal conforms to ANSI CRT programming standards. REGIS 2000000 Terminal has REGIS CRT capabilities. BLOCK 4000000 Block mode terminal. AVO 8000000 Terminal has advanced video. EDIT 10000000 Terminal has local edit capabilities. DECCRT 20000000 Terminal is a DIGITAL CRT. DECCRT2 40000000 Terminal is a DIGITAL CRT Level 2. DECCRT3 80000000 Terminal is a DIGITAL CRT Level 3. The defaults are AUTOBAUD and EDITING. 2 TTY_DEFPORT TTY_DEFPORT provides flag bits for port drivers. Bit 0 set to 1 indicates that the terminal controller does not provide automatic XON/XOFF flow control. This bit should not be set for Compaq controllers, but it is needed for some foreign controllers. Currently only the YCDRIVER (DMF32, DMZ32) uses this bit. The remaining bits are reserved for future use. This special parameter should be modified only if recommended by Compaq. 2 TTY_DIALTYPE TTY_DIALTYPE provides flag bits for dialups. Bit 0 is 1 for United Kingdom dialups and 0 for all others. Bit 1 controls the modem protocol used. Bit 2 controls whether a modem line hangs up 30 seconds after seeing CARRIER if a channel is not assigned to the device. The remaining bits are reserved for future use. See the OpenVMS I/O User's Reference Manual for more information about flag bits. 2 TTY_DMASIZE TTY_DMASIZE specifies a number of characters in the output buffer. Below this number, character transfers are performed; above this number, DMA transfers occur if the controller is capable of DMA I/O. TTY_DMASIZE is a DYNAMIC parameter. 2 TTY_PARITY TTY_PARITY sets terminal default parity. 2 TTY_RSPEED TTY_RSPEED defines the receive speed for terminals. If TTY_ RSPEED is 0, TTY_SPEED controls both the transmit and the receive speed. Maximum value is 17. This parameter is only applicable for controllers that support split-speed operations, such as the DZ32 and the DMF32. 2 TTY_SCANDELTA TTY_SCANDELTA sets the interval for polling terminals for dialup and hangup events. Shorter intervals use more processor time; longer intervals may result in missing a hangup event. 2 TTY_SILOTIME TTY_SILOTIME defines the interval at which the DMF32 hardware polls the input silo for received characters. The DMF32 asynchronous terminal controller can delay the generation of a single input interrupt until multiple characters have accumulated in the input silo. TTY_SILOTIME specifies the number of milliseconds that the characters are allowed to accumulate prior to the generation of an input interrupt by the hardware. 2 TTY_SPEED TTY_SPEED sets the systemwide default speed for terminals. Low byte is transmit speed, and high byte is receive speed. If high byte is set to 0, receive speed is identical to transmit speed. Maximum value is 17. Baud rates are defined by the $TTDEF macro. 2 TTY_TIMEOUT TTY_TIMEOUT sets the number of seconds before a process associated with a disconnected terminal is deleted. The default value (900 seconds) is usually adequate. Note that using values for TTY_TIMEOUT greater than one year (value %X01E13380) can cause overflow errors and result in a disconnected device timing out immediately. TTY_TIMEOUT is a DYNAMIC parameter. 2 TTY_TYPAHDSZ TTY_TYPAHDSZ sets the size of the terminal type-ahead buffer. The default value is usually adequate. Do not exceed the maximum value of 32767 when setting this parameter. 2 UAFALTERNATE UAFALTERNATE enables or disables the assignment of SYSUAF as the logical name for SYSUAFALT, causing all references to the user authorization file (SYSUAF) to be translated to SYS$SYSTEM:SYSUAFALT. Use of the normal user authorization file (SYS$SYSTEM:SYSUAF) can be restored by deassigning the system logical name SYSUAF. This parameter should be set on (1) only when the system is being used by a restricted set of users. You must create a user authorization file named SYSUAFALT prior to setting UAFALTERNATE to 1. UAFALTERNATE has the GEN and MAJOR attributes. 2 UDABURSTRATE UDABURSTRATE is reserved for Compaq use only. UDABURSTRATE has the GEN attribute. 2 USERD1 USERD1 is reserved for definition at the user's site. The reserved longword is referenced by the symbol SGN$GL_USERD1. On Alpha systems, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module. On VAX systems, the symbol is in the SYS$SYSTEM:SYS.STB module. USERD1 is a DYNAMIC parameter. 2 USERD2 USERD2 is reserved for definition at the user's site. The reserved longword is referenced by the symbol SGN$GL_USERD2. On Alpha systems, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module. On VAX systems, the symbol is in the SYS$SYSTEM:SYS.STB module. USERD2 is a DYNAMIC parameter. 2 USER3 USER3 is a parameter that is reserved for definition at the user's site. The reserved longword is referenced by the symbol SGN$GL_USER3. On Alpha systems, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module. On VAX systems, the symbol is in the SYS$SYSTEM:SYS.STB module. 2 USER4 USER4 is a parameter that is reserved for definition at the user's site. The reserved longword is referenced by the symbol SGN$GL_USER4. On Alpha systems, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module. On VAX systems, the symbol is in the SYS$SYSTEM:SYS.STB module. 2 VAXCLUSTER VAXCLUSTER controls loading of the cluster code. Specify one of the following: Value Description 0 Never form or join a cluster. 1 Base decision of whether to form (or join) a cluster or to operate standalone on the presence of cluster hardware. 2 Always form or join a cluster. The default value is 1. VAXCLUSTER is an AUTOGEN parameter. 2 VBN_CACHE_S (VAX only) This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. The static system parameter VBN_CACHE_S enables or disables file system data caching. By default its value is 1, which means that caching is enabled and the Virtual I/O Cache is loaded during system startup. Setting the value to 0 disables file system data caching on the local node and throughout the OpenVMS Cluster. In an OpenVMS Cluster, none of the other nodes in the cluster can cache any file data until this node either leaves the cluster or reboots with VBN_CACHE_S set to 1. 2 VBSS_ENABLE (VAX only) This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. This parameter enables virtual balance slots (VBS) to be created. A virtual balance slot holds the mapping for a memory- resident process that does not currently own a real balance slot (RBS). The set of real balance slots is timeshared among all memory-resident processes. With VBS enabled, the quantity of memory-resident processes is limited by the system parameter MAXPROCESSCNT. With VBS disabled, the quantity of memory-resident processes is limited by the system parameter BALSETCNT. When creating a new process, if the set of real balance slots is allocated, then a virtual balance slot is created and the owner of a real balance slot is selected and transitioned to the virtual balance slot. The new process is created in the real balance slot. Processes are transitioned (faulted) back to a real balance slot as they are scheduled to execute on a CPU. Bit Result 0 Enables VBS. All other VBS enables are subordinate to this enable. The default is disabled. 1 Enables the creation of a map for process-based direct I/O, allowing the process with direct I/O (DIO) outstanding to be transitioned to a virtual balance slot. Without DIO maps, a process with DIO outstanding retains its real balance slot for the duration of the DIO. This reduces the pool of available real balance slots for timesharing, which may result in a higher rate of faulting into the limited set of real balance slots. The default is enabled. 2-7 Reserved to Compaq for future use. VBSS_ENABLE is an AUTOGEN parameter. 2 VBSS_ENABLE2 (VAX only) This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. This cell is used for enabling and disabling VBS dynamic capabilities that are valid only when VBS is enabled. The following table indicates the result for each value: Bit Result 0 Enables VBS to perform first-level data reduction when switching processes. The default is enabled. 1 Enables VBS to perform second-level data reduction when switching processes. The default is enabled. 2 Requests VBS to perform an optimization that detects empty private page table pages on the modified list and frees them directly to the free list versus writing them to the page file. The default setting is enabled. 3-7 Reserved to Compaq for future use. 2 VCC_FLAGS (Alpha only) The static system parameter VCC_FLAGS enables and disables file system data caching. If caching is enabled, VCC_ FLAGS controls which file system data cache is loaded during system startup. Value Description 0 Disables file system data caching on the local node and throughout the OpenVMS Cluster. In an OpenVMS Cluster, if caching is disabled on any node, none of the other nodes can use the Extended File Cache or the Virtual I/O Cache. They can't cache any file data until that node either leaves the cluster or reboots with VCC_FLAGS set to a nonzero value. 1 Enables file system data caching and selects the Virtual I/O Cache. This is the default for VAX systems. 2 Enables file system data caching and selects the Extended File Cache. This is the default for Alpha systems. VCC_FLAGS is an AUTOGEN parameter. 2 VCC_MAXSIZE (Alpha only) The static system parameter VCC_MAXSIZE controls the size of the virtual I/O cache. VCC_MAXSIZE, which specifies the size in blocks, is 6,400 by default. The virtual I/O cache cannot shrink or grow. Its size is fixed at system startup. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. VCC_MAXSIZE is an AUTOGEN parameter. 2 VCC_MAX_CACHE (Alpha only) The dynamic system parameter VCC_MAX_CACHE controls the maximum size of the Extended File Cache. It specifies the size in megabytes. By default, VCC_MAX_CACHE has a special value of -1 for people who do not want to tune their systems manually; this value means that at system startup, the maximum size of the Extended File Cache is set to 50 percent of the physical memory on the system. The Extended File Cache can automatically shrink and grow, depending on your I/O workload and how much spare memory your system has. As your I/O workload increases, the cache automatically grows, but never to more than the maximum size. When your application needs memory, the cache automatically shrinks. The value of VCC_MAX_CACHE at system startup sets an upper limit for the maximum size of the Extended File Cache. You cannot increase the maximum size of VCC_MAX_CACHE beyond its value at boot time. For example, if VCC_MAX_CACHE is 60 MB at system startup, you can then set VCC_MAX_CACHE to 40, which decreases the maximum size to 40 MB. If you then set VCC_MAX_CACHE to 80, the maximum size is only increased to 60 MB, the value set at system startup. Note that VCC_MAX_CACHE is a semi-dynamic parameter. If you change its value, you must enter the DCL command SET CACHE/RESET for any changes to take effect immediately. Otherwise, it might take much more time for the changes to take effect. If you are using the reserved memory registry to allocate memory permanently, you must set the VCC$MIN_CACHE_SIZE entry in the reserved memory registry to a value less than or equal to VCC_MAX_CACHE at system startup time. Refer to the OpenVMS System Manager's Manual for instructions on setting permanent memory allocations for the cache. VCC_MAX_CACHE is a DYNAMIC parameter. 2 VCC_MAX_IO_SIZE (Alpha only) The dynamic system parameter VCC_MAX_IO_SIZE controls the maximum size of I/O that can be cached by the Extended File Cache. It specifies the size in blocks. By default, the size is 127 blocks. Changing the value of VCC_MAX_IO_SIZE affects reads and writes to volumes currently mounted on the local node, as well as reads and writes to volumes mounted in the future. If VCC_MAX_IO_SIZE is 0, the Extended File Cache on the local node cannot cache any reads or writes. However, the system is not prevented from reserving memory for the Extended File Cache during startup if a VCC$MIN_CACHE_SIZE entry is in the reserved memory registry. VCC_MAX_IO_SIZE is a DYNAMIC parameter. 2 VCC_MAX_LOCKS (Alpha only) VCC_MAX_LOCKS is a special parameter reserved for Compaq use only. Extended File Cache intends to use this parameter in future versions. 2 VCC_MINSIZE (VAX only) VCC_MINSIZE sets the lower limit in pages of memory used by virtual I/O cache. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 VCC_PTES (VAX only) The static system parameter VCC_PTES controls the maximum size of the virtual I/O cache. It specifies the potential size in pages. The virtual I/O cache automatically shrinks and grows, depending on your I/O workload and how much spare memory your system has. As your I/O workload increases, the cache automatically grows, but never to more than the maximum size. When your applications need memory, the cache automatically shrinks. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 VCC_READAHEAD (Alpha only) The dynamic system parameter VCC_READAHEAD controls whether the Extended File Cache can use read-ahead caching. Read- ahead caching is a technique that improves the performance of applications that read data sequentially. By default VCC_READAHEAD is 1, which means that the Extended File Cache can use read-ahead caching. The Extended File Cache detects when a file is being read sequentially in equal-sized I/Os, and fetches data ahead of the current read, so that the next read instruction can be satisfied from cache. To stop the Extended File Cache from using read-ahead caching, set VCC_READAHEAD to 0. Changing the value of VCC_READAHEAD affects volumes currently mounted on the local node, as well as volumes mounted in the future. Readahead I/Os are totally asynchronous from user I/Os and only take place if sufficient system resources are available. VCC_READAHEAD is a DYNAMIC parameter. 2 VCC_WRITEBEHIND (Alpha only) VCC_WRITEBEHIND is reserved for Compaq use only. Extended File Cache intends to use this parameter in future versions. 2 VCC_WRITE_DELAY (Alpha only) VCC_WRITE_DELAY is reserved for Compaq use only. 2 VECTOR_MARGIN (VAX only) VECTOR_MARGIN establishes the time interval when the system checks the status of all vector consumers. The VECTOR_MARGIN parameter accepts an integer value between 1 and FFFFFFFF(16). This value represents a number of consecutive process quanta (as determined by the system parameter QUANTUM). If the process has not issued any vector instructions in the specified number of quanta, the system declares it a marginal vector consumer. The default value of the VECTOR_MARGIN parameter is 200 subscript 10. VECTOR_MARGIN is a DYNAMIC parameter. 2 VECTOR_PROC (VAX only) VECTOR_PROC controls loading of vector processing support code. By default, in a VAX vector processing system, the system automatically loads the vector processing support code at boot time. You can override the default behavior by setting the static system parameter VECTOR_PROC to one of the following values: Value Result 0 Do not load the vector processing support code, regardless of the system configuration. 1 Load the vector processing support code if at least one vector-present processor exists. This is the default value. 2 Load the vector processing support code if the system is vector-capable. This setting is most useful for a system in which processors have separate power supplies. With this setting, you can reconfigure a vector processor into the system without rebooting the operating system. 3 Always load the vector processing support code. This parameter is not used on Alpha systems. 2 VIRTUALPAGECNT On VAX systems, VIRTUALPAGECNT sets the maximum number of virtual pages that can be mapped for any one process. A program is allowed to divide its virtual space between the P0 and P1 tables in any proportion. If you use SYS$UPDATE:LIBDECOMP.COM to decompress libraries and the VIRTUALPAGECNT setting is low, make sure you set the PGFLQUOTA field in the user authorization file to at least twice the size of the library. At installation time, AUTOGEN automatically sets an appropriate value for VIRTUALPAGECNT. The value depends on the particular configuration-the type and number of graphics adapters on the system, if any exist. You cannot set VIRTUALPAGECNT below the minimum value required for your graphics configuration. Because the VIRTUALPAGECNT setting supports hardware address space rather than system memory, do not use the value of VIRTUALPAGECNT that AUTOGEN sets to gauge the size of your page file. Starting with OpenVMS Version 7.0, VIRTUALPAGECNT has been an obsolete parameter on Alpha systems. Note, however, that the parameter remains in existence on Alpha systems for compatibility purposes and has a default and maximum value of %X7FFFFFFF. SYSBOOT and AUTOGEN enforce this default value. VIRTUALPAGECNT has the AUTOGEN, GEN, and MAJOR attributes. 2 VMS VMSD1, VMSD2, VMSD3, VMSD4, VMS5, VMS6, VMS7, and VMS8 are special parameters reserved for Compaq use. VMSD1 through VMSD4 are dynamic. 2 VOTES VOTES establishes the number of votes an OpenVMS Cluster member system contributes to a quorum. VOTES has the AUTOGEN attribute. 2 WBM_MSG_INT WBM_MSG_INT is one of three system parameters that are available for managing the update traffic between a master write bitmap and its corresponding local write bitmaps in an OpenVMS Cluster system. The others are WBM_MSG_UPPER and WBM_MSG_LOWER. These parameters set the interval at which the frequency of sending messages is tested and also set an upper and lower threshold that determine whether the messages are grouped into one SCS message or are sent one by one. In single-message mode, WBM_MSG_INT is the time interval in milliseconds between assessments of the most suitable write bitmap message mode. In single-message mode, the writes issued by each remote node are, by default, sent one by one in individual SCS messages to the node with the master write bitmap. If the writes sent by a remote node reach an upper threshhold of messages during a specified interval, single-message mode switches to buffered-message mode. In buffered-message mode, WBM_MSG_INT is the maximum time a message waits before it is sent. In buffered-message mode, the messages are collected for a specified interval and then sent in one SCS message. During periods of increased message traffic, grouping multiple messages to send in one SCS message to the master write bitmap is generally more efficient than sending each message separately. The minimum value of WBM_MSG_INT is 10 milliseconds. The maximum value is -1, which corresponds to the maximum positive value that a longword can represent. The default is 10 milliseconds. WBM_MSG_INT is a DYNAMIC parameter. 2 WBM_MSG_LOWER WBM_MSG_LOWER is one of three system parameters that are available for managing the update traffic between a master write bitmap and its corresponding local write bitmaps in an OpenVMS Cluster system. The others are WBM_MSG_INT and WBM_MSG_ UPPER. These parameters set the interval at which the frequency of sending messages is tested and also set an upper and lower threshold that determine whether the messages are grouped into one SCS message or are sent one by one. WBM_MSG_LOWER is the lower threshold for the number of messages sent during the test interval that initiates single-message mode. In single-message mode, the writes issued by each remote node are, by default, sent one by one in individual SCS messages to the node with the master write bitmap. If the writes sent by a remote node reach an upper threshhold of messages during a specified interval, single-message mode switches to buffered- message mode. The minimum value of WBM_MSG_LOwer is 0 messages per interval. The maximum value is -1, which corresponds to the maximum positive value that a longword can represent. The default is 10. WBM_MSG_LOWER is a DYNAMIC parameter. 2 WBM_MSG_UPPER WBM_MSG_UPPER is one of three system parameters that are available for managing the update traffic between a master write bitmap and its corresponding local write bitmaps in an OpenVMS Cluster system. The others are WBM_MSG_INT and WBM_MSG_ LOWER. These parameters set the interval at which the frequency of sending messages is tested and also set an upper and lower threshold that determine whether the messages are grouped into one SCS message or are sent one by one. WBM_MSG_UPPER is the upper threshold for the number of messages sent during the test interval that initiates buffered-message mode. In buffered-message mode, the messages are collected for a specified interval and then sent in one SCS message. The minimum value of WBM_MSG_UPPER is 0 messages per interval. The maximum value is -1, which corresponds to the maximum positive value that a longword can represent. The default is 100. WBM_MSG_UPPER is a DYNAMIC parameter. 2 WBM_OPCOM_LVL WBM_OPCOM_LVL controls whether write bitmap system messages are sent to the operator console. Possible values are shown in the following table: Value Description 0 Messages are turned off. 1 The default; messages are provided when write bitmaps are started, deleted, and renamed, and when the SCS message mode (buffered or single) changes. 2 All messages for a setting of 1 are provided plus many more. WBM_OPCOM_LVL is a DYNAMIC parameter. 2 WINDOW_SYSTEM WINDOW_SYSTEM specifies the windowing system to be used on a workstation. Specify one of the following values: Value Description 1 Load the DECwindows Motif for OpenVMS workstation environment. 2 Load the UIS workstation environment. WINDOW_SYSTEM is a DYNAMIC parameter. 2 WLKSYSDSK (Alpha only) WLKSYSDSK is used by various bootstrap components to determine if the system disk should be treated as though it is write-locked. This parameter is used primarily to allow OpenVMS to boot from a CD. 2 WPRE_SIZE WPRE_SIZE represents the number of pages to be allocated to accommodate WatchPoint Recovery Entries (WPRE) on the Watchpoint Driver. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. WPRE_SIZE is a DYNAMIC parameter. 2 WPTTE_SIZE WPTTE_SIZE is the number of entries that the WPDRIVER creates in the WatchPoint Trace Table. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. WPTTE_SIZE is a DYNAMIC parameter. 2 WRITABLESYS WRITABLESYS controls whether system code is writable. This parameter is set (value of 1) for debugging purposes only. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 WRITESYSPARAMS On VAX systems, WRITESYSPARAMS indicates that parameters are modified during SYSBOOT and are written out to VAXVMSSYS.PAR by STARTUP.COM. On Alpha systems, WRITESYSPARAMS indicates that parameters are modified during SYSBOOT and are written out to ALPHAVMSSYS.PAR by STARTUP.COM. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. WRITESYSPARAMS is a DYNAMIC parameter. 2 WSDEC Increasing the value of this parameter tends to increase the speed with which working set limits are decreased when the need arises. On VAX systems, WSDEC specifies the number of pages by which the limit of a working set is automatically decreased at each adjustment interval (which is quantum end). At a setting of 35, for example, the system decreases the limit of a working set by 35 pages each time a decrease is required. On Alpha systems, WSDEC specifies the number of pagelets by which the limit of a working set is automatically decreased at each adjustment interval (which is quantum end). At a setting of 35, for example, the system decreases the limit of a working set by 35 pagelets each time a decrease is required. WSDEC has the AUTOGEN, DYNAMIC, and MAJOR attributes. 2 WSINC Decreasing the value of this parameter tends to reduce the speed with which working set limits are increased when the need arises. Normally, you should keep this parameter at a high value because a rapid increase in limit is often critical to performance. On VAX systems, WSINC specifies the number of pages by which the limit of a working set is automatically increased at each adjustment interval (which is quantum end). At a setting of 150, for example, the system increases the limit of a working set by 150 pages each time an increase is required. On VAX systems, the default value is 150 512-byte pages. On Alpha systems, WSINC specifies the number of pagelets by which the limit of a working set is automatically increased at each adjustment interval (which is quantum end). At a setting of 150, for example, the system increases the limit of a working set by 150 pagelets each time an increase is required. On Alpha systems, the default value is 2400 512-byte pagelets (150 8192-byte Alpha pages). A value of 0 for WSINC disables the automatic adjustment of working set limits for all processes. Limits stay at their base values. You can disable the automatic adjustment of working set limits on a per-process basis by using the DCL command SET WORKING_SET. WSINC has the DYNAMIC and MAJOR attributes. On Alpha systems, WSINC also has the AUTOGEN attribute. 2 WSMAX WSMAX sets the maximum number of pages on a systemwide basis for any working set. WSMAX is calculated as a quarter of the first 32 MB plus a sixteenth of the memory from 32 to 256 MB, plus a sixty-fourth of the memory (if any) above 256 MB. This is intended to assist managers of systems that host large numbers of users whose working sets are not large. Systems whose user bases consist of a small number of users (or processes) that require large amounts of physical memory (for example, simulations) might need to set MIN_WSMAX to a value that satisfies the requirements of those processes. WSMAX has the AUTOGEN, GEN, and MAJOR attributes. 2 WS_OPA0 (VAX only) WS_OPA0 enables OPA0 output to the QVSS screen for a workstation. A value of 1 enables output for OPA0 to the QVSS screen; a value of 0 causes output for OPA0 to be ignored. 2 XFMAXRATE XFMAXRATE limits the data transfer rate that can be set for DR32 devices. On some hardware configurations (especially those without interleaved memory), a high DR32 transfer rate could cause a machine check (CPU timeout). The OpenVMS I/O User's Reference Manual describes how to encode this parameter. WSMAXRATE is a DYNAMIC parameter. 2 XQPCTL2 XQPCTL2 controls improved concurrency. The default value of XQPCTL2 is 1, which turns on improved concurrency. Setting XQPCTL2 to 0 turns off improved concurrency. This parameter affects local access to the extent and file ID caches. This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 XQPCTLD1 XQPCTLD1 controls multithreading, which can be used only by PATHWORKS servers. The default value of XQPCTLD1 is 8, which enables multithreading. Setting XQPCTLD1 to 0 disables multithreading, This special parameter is used by Compaq and is subject to change. Do not change this parameter unless Compaq recommends that you do so. 2 ZERO_LIST_HI (Alpha only) ZERO_LIST_HI is the maximum number of pages zeroed and put on the zeroed page list. This list is used as a cache of pages containing all zeros, which improves the performance of allocating such pages. ZERO_LIST_HI has the AUTOGEN and DYNAMIC attributes. ! ********************************************************************* ! PARAM-END! PARAM-INSERT ! HELP on the individual parameters is taken from SYSGEN and ! is inserted here by the build procedures. Please do not edit the ! first comment line. !****************************************************************************