VMS Help
Sys Parameters
*Conan The Librarian (sorry for the slow response - running on an old VAX)
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Help is provided for the system parameters listed below.
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.
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.
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.
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.
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.
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.
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.
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.
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.
ACP_MAXREAD sets the maximum number of directory blocks read in
one I/O operation.
ACP_MAXREAD is a DYNAMIC parameter.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(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.
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.
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.
(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.
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.
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.
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.
(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.)
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.
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.
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.
(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.)
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.
DEFMBXBUFQUO sets the default for the mailbox buffer quota size
in bytes when this value is not specified in a Create Mailbox
($CREMBX) system service call.
DEFMBXBUFQUO is a DYNAMIC parameter.
DEFMBXMXMSG sets the default for the mailbox maximum message size
in bytes when this value is not specified in a Create Mailbox
($CREMBX) system service call.
DEFMBXMXMSG is a DYNAMIC parameter.
DEFPRI sets the base default priority for processes.
DEFPRI is a DYNAMIC parameter.
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.
(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.
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.
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.
(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.
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.
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.
(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.
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.
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.
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.
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.
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.
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.
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.
(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.
(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.
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.
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.
(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.
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.
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.
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.
(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.
(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.
(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.
(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.
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.
(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).
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.
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.
IEEE_ADDRESS is reserved for Compaq use only.
IEEE_ADDRESSH is reserved for Compaq use only.
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.
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.
(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.
(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.
(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.
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.
This parameter is no longer in use.
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.
KFILSTCNT is no longer used on VAX systems and is not used on
Alpha systems.
(Alpha only) KSTACKPAGES controls the number of pages allocated
for process kernel stacks.
(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.
(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.
(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.
(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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
LOCKDIRWT determines the portion of lock manager directory that
this system handles. The default value is usually adequate.
LOCKDIRWT is an AUTOGEN parameter.
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.
LOCKIDTBL_MAX is obsolete beginning with OpenVMS Version 7.1.
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.
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.
This parameter has been obsolete since OpenVMS Version 6.0.
This parameter has been obsolete since OpenVMS Version 6.0.
(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.
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.
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.
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.
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.
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.
(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.
(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.
(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.
(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.
(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.
(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.
(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.
(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.
(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.
(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.
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.
This parameter is not used on OpenVMS VAX or Alpha systems.
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.
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.
(Alpha only) MPDEV_D1 is reserved for use by the operating
system.
(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.
(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.
(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.
(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.
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.
MPW_IOLIMIT specifies the number of outstanding I/Os to the
modified-page writer.
On Alpha systems, MPW_IOLIMIT is an AUTOGEN-altered parameter.
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.
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.
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.
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.
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.
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.
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.
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.
MSCP_CREDITS specifies the number of outstanding I/O requests
that can be active from one client system.
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.
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.
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.
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.
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.
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.
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.
Beginning in OpenVMS Version 7.3, this parameter is obsolete.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(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.
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.
(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.
(Alpha only) NPAG_BAP_MAX is the maximum of bus addressable pool
sizes requested.
(Alpha only) NPAG_BAP_MAX_PA is the smallest of the maximum bus
addressable pool physical addresses requested.
(Alpha only) NPAG_BAP_MIN is the minimum of bus addressable pool
sizes requested.
(Alpha only) NPAG_BAP_MIN_PA specifies the lowest physical
address allowed within a bus addressable pool.
(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.
(Alpha only) NPAG_INTERVAL is the number of seconds between
passes of nonpaged pool gentle reclamation.
NPAG_INTERVAL is a DYNAMIC parameter.
(Alpha only) NPAG_RING_SIZE represents the number of entries in
the ring buffer.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(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.
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.
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.
(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.
(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.
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.
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.
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.
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.
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.
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.
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 ($CREPRC) system service or
the DCL command RUN (Process).
PQL_DBIOLM has the DYNAMIC and GEN attributes.
PQL_DBYTLM sets the default buffered I/O byte count limit for the
amount of buffered space available to a process created by the
Create Process ($CREPRC) system service or the DCL command RUN
(Process).
PQL_DBYTLM has the DYNAMIC and GEN attributes.
PQL_DCPULM sets the default CPU time limit for a process created
by the Create Process ($CREPRC) system service or the DCL command
RUN (Process). PQL_DCPULM specifies the time limit in increments
of 10 milliseconds.
The default value of 0 imposes no limit on CPU time usage and is
typically the correct value for this parameter.
PQL_DCPULM has the DYNAMIC and GEN attributes.
PQL_DDIOLM sets the default direct I/O limit for a process
created by the Create Process ($CREPRC) system service or the
DCL command RUN (Process).
PQL_DDIOLM has the DYNAMIC and GEN attributes.
PQL_DENQLM sets the default enqueue limit for a process created
by the Create Process ($CREPRC) system service or the DCL command
RUN (Process).
PQL_DENQLM has the DYNAMIC and GEN attributes.
PQL_DFILLM sets the default open file limit for a process created
by the Create Process ($CREPRC) system service or the DCL command
RUN (Process).
PQL_DFILLM has the DYNAMIC and GEN attributes.
PQL_DJTQUOTA sets the default job table byte count quota for a
process created by the Create Process ($CREPRC) system service or
the DCL command RUN (Process). PQL_DJTQUOTA specifies the number
of bytes of paged pool allocated to the job table. The default
value is usually adequate, unless a large number of job logical
names or temporary mailboxes are used.
PQL_DJTQUOTA is a DYNAMIC parameter.
PQL_DPGFLQUOTA sets the default page file quota for a process
created by the Create Process ($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.
PQL_DPRCLM sets the default subprocess limit for a process
created by the Create Process ($CREPRC) system service or the
DCL command RUN (Process).
PQL_DPRCLM has the DYNAMIC and GEN attributes.
PQL_DTQELM sets the default number of timer queue entries for a
process created by the Create Process ($CREPRC) system service or
the DCL command RUN (Process).
PQL_DTQELM has the DYNAMIC and GEN attributes.
PQL_DWSDEFAULT sets the default working set size for a process
created by the Create Process ($CREPRC) system service or the DCL
command RUN (Process).
PQL_DWSDEFAULT has the AUTOGEN and GEN attributes.
PQL_DWSEXTENT sets the default working set extent for a process
created by the Create Process ($CREPRC) system service or the DCL
command RUN (Process).
PQL_DWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes.
PQL_DWSQUOTA sets the default working set quota for a process
created by the Create Process ($CREPRC) system service or the DCL
command RUN (Process).
PQL_DWSQUOTA has the AUTOGEN, DYNAMIC, and GEN attributes.
PQL_MASTLM sets a default limit on the minimum number of pending
ASTs for a process created by the Create Process ($CREPRC) system
service or the DCL command RUN (Process).
PQL_MASTLM has the DYNAMIC and GEN attributes.
PQL_MBIOLM sets the minimum buffered I/O limit for a process
created by the Create Process ($CREPRC) system service or the DCL
command RUN (Process).
PQL_MBIOLM has the DYNAMIC and GEN attributes.
PQL_MBYTLM sets the minimum buffered I/O byte limit for a process
created by the Create Process ($CREPRC) system service or the DCL
command RUN (Process).
PQL_MBYTLM has the DYNAMIC and GEN attributes.
PQL_MCPULM sets the minimum CPU time limit in increments of
10 milliseconds for a process created by the Create Process
($CREPRC) system service or the DCL command RUN (Process).
PQL_MCPULM has the DYNAMIC and GEN attributes.
PQL_MDIOLM sets the minimum direct I/O limit for a process
created by the Create Process ($CREPRC) system service or the
DCL command RUN (Process).
PQL_MDIOLM has the DYNAMIC and GEN attributes.
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 ($CREPRC) system service or the DCL command RUN
(Process).
PQL_MENQLM has the DYNAMIC and GEN attributes.
PQL_MFILLM sets the minimum open file limit for a process created
by the Create Process ($CREPRC) system service or the DCL command
RUN (Process).
PQL_MFILLM has the DYNAMIC and GEN attributes.
PQL_MJTQUOTA sets the minimum job table byte count quota for a
process created by the Create Process ($CREPRC) system service or
the DCL command RUN (Process).
PQL_MJTQUOTA is a DYNAMIC parameter.
On VAX systems, PQL_MPGFLQUOTA sets the minimum page file quota
for a process created by the Create Process ($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 ($CREPRC)
system service or the DCL command RUN (Process).
PQL_MPQFLQUOTA has the DYNAMIC and GEN attributes. On VAX
systems, PQL_MPQFLQUOTA is also an AUTOGEN parameter.
PQL_MPRCLM sets the minimum subprocess limit for a process
created by the Create Process ($CREPRC) system service or the
DCL command RUN (Process).
PQL_MPRCLM has the DYNAMIC and GEN attributes.
PQL_MTQELM sets the minimum number of timer queue entries for a
process created by the Create Process ($CREPRC) system service or
the DCL command RUN (Process).
PQL_MTQELM has the DYNAMIC and GEN attributes.
PQL_MWSDEFAULT sets the minimum default working set size for a
process created by the Create Process ($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.
PQL_MWSEXTENT sets the minimum working set extent for a process
created by the Create Process ($CREPRC) system service or the DCL
command RUN (Process).
This value overrides a smaller quantity set for a user in
AUTHORIZE.
PQL_MWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes.
PQL_MWSQUOTA sets the minimum working set quota for a process
created by the Create Process ($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.
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.
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.
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.
(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.
PU_OPTIONS is reserved for Compaq use only.
(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.
QDSKINTERVAL establishes, in seconds, the disk quorum polling
interval. The default value is 3.
QDSKVOTES specifies the number of votes contributed by a quorum
disk in a cluster.
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.
(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.
(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.
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.
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.
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.
RJOBLIM defines the maximum number of remote terminals allowed in
the system at any one time.
RJOBLIM is a DYNAMIC parameter.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
(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).
SA_APP is a special parameter reserved for Compaq use only.
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.
(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.
(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.
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.
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.
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.
(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.
(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.
This parameter is reserved for Compaq use only.
SCSMAXDG has the GEN attribute.
This parameter is reserved for Compaq use only.
SCSMAXMSG has the GEN attribute.
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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
(Alpha only) SHADOW_REMOVE_1 is reserved for Compaq use only.
(Alpha only) SHADOW_REMOVE_2 is reserved for Compaq use only.
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.
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.
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.
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.
(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.
(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.
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.
SMP_CPUSH is a special parameter reserved for Compaq use only.
Compaq recommends that you use the default value.
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).
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).
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).
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.
(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.
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.
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.
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.
(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.
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.
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.
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.
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.
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.
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.
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.
TAILORED specifies whether or not the system is tailored during
installation. Compaq recommends that you use the default value.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
TTY_AUTOCHAR sets the character the terminal driver echoes when
the job controller has been notified.
TTY_AUTOCHAR is a DYNAMIC parameter.
TTY_BUF sets the default line width for terminals.
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.
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.
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.
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.
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.
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.
TTY_PARITY sets terminal default parity.
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.
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.
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.
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 $TTDEF macro.
TTY_TIMEOUT sets the number of seconds before a process
associated with a disconnected terminal is deleted. The default
value (900 seconds) is usually adequate. Note that using values
for TTY_TIMEOUT greater than one year (value %X01E13380) can
cause overflow errors and result in a disconnected device timing
out immediately.
TTY_TIMEOUT is a DYNAMIC parameter.
TTY_TYPAHDSZ sets the size of the terminal type-ahead buffer.
The default value is usually adequate. Do not exceed the maximum
value of 32767 when setting this parameter.
UAFALTERNATE enables or disables the assignment of SYSUAF
as the logical name for SYSUAFALT, causing all references
to the user authorization file (SYSUAF) to be translated to
SYS$SYSTEM:SYSUAFALT. Use of the normal user authorization file
(SYS$SYSTEM:SYSUAF) can be restored by deassigning the system
logical name SYSUAF. This parameter should be set on (1) only
when the system is being used by a restricted set of users. You
must create a user authorization file named SYSUAFALT prior to
setting UAFALTERNATE to 1.
UAFALTERNATE has the GEN and MAJOR attributes.
UDABURSTRATE is reserved for Compaq use only.
UDABURSTRATE has the GEN attribute.
USERD1 is reserved for definition at the user's site. The
reserved longword is referenced by the symbol SGN$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$SYSTEM:SYS.STB module.
USERD1 is a DYNAMIC parameter.
USERD2 is reserved for definition at the user's site. The
reserved longword is referenced by the symbol SGN$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$SYSTEM:SYS.STB module.
USERD2 is a DYNAMIC parameter.
USER3 is a parameter that is reserved for definition at the
user's site. The reserved longword is referenced by the symbol
SGN$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$SYSTEM:SYS.STB module.
USER4 is a parameter that is reserved for definition at the
user's site. The reserved longword is referenced by the symbol
SGN$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.
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.
(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.
(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.
(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.
(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.
(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.
(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.
(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.
(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.
(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.
(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.
(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.
(Alpha only) VCC_WRITEBEHIND is reserved for Compaq use only.
Extended File Cache intends to use this parameter in future
versions.
(Alpha only) VCC_WRITE_DELAY is reserved for Compaq use only.
(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.
(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.
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.
VMSD1, VMSD2, VMSD3, VMSD4, VMS5, VMS6, VMS7, and VMS8 are
special parameters reserved for Compaq use. VMSD1 through VMSD4
are dynamic.
VOTES establishes the number of votes an OpenVMS Cluster member
system contributes to a quorum.
VOTES has the AUTOGEN attribute.
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.
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.
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.
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.
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.
(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.
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.
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.
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.
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.
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.
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.
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.
(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.
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.
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.
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.
(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.
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