crashconf(2)crashconf(2)NAMEcrashconf() - configure system crash dumps
SYNOPSISDESCRIPTION
changes the current system crash dump configuration. The crash dump
configuration consists of:
· The crash dump device list. This list identifies all devices that
can be used to store a crash dump. The devices are used in reverse
order, last specified to first.
· The included class list. This list identifies all system memory
classes that must be included in any crash dump.
· The excluded class list. This list identifies all system memory
classes that should not be included in a crash dump.
· The compression mode selection. This selection is used to turn com‐
pression or before dumping.
· The concurrency mode selection. This selection is used to turn con‐
currency or before dumping.
Most system memory classes are in neither the included class list nor
the excluded class list. Instead, the system determines whether or not
to dump those classes of memory based on the type of crash that occurs.
Note the system operator may request a full crash dump at the time the
dump is taken. In this case, a full dump will be performed regardless
of the contents of the excluded class list.
Turning compression mode will result in smaller and faster dumps.
Copying of compressed dump from the dump device over to the filesystem
will also be faster using
Since compressed dump requires additional processors and memory to do
the compression, the system may fall back on uncompressed dump if it is
not able to identify the processing resources required to do compressed
dump after a system crash.
Turning concurrency mode may result in faster dumps depending on the
configuration of the dump devices.
Depending on the availability of additional memory and the configura‐
tion of dump devices, the system may fall back to non-concurrent dump
mode.
Configuration changes made using take effect immediately and remain in
effect until the next system reboot, or until changed with a subsequent
call to Using the operation, the dump device list can be made persis‐
tent across system reboots. Persistent dump devices information is
maintained in the kernel registry services (KRS, see krs(5)).
Parameters
operation is a bitmask specifying what should do. It must have at
least one of the following flags set:
will change the contents of the included class list. The
includeClasses parameter is valid.
will change the contents of the excluded class list.
The excludeClasses parameter is valid.
will change the contents of the crash dump device list. The
deviceCount, devices and deviceReturn parameters are
valid.
will set the compression mode
will set the compression mode
will set the concurrency mode
will set the concurrency mode
will mark the current dump device list as persistent. Once this
is
used, from the next boot onwards, system will ignore
devices marked for dump using and Instead, the persistent
device list is used.
will change dump configuration mode.
From next boot onwards devices marked for dump using and
will be configured as dump devices during boot-up. Mark‐
ing dump devices using and will be obsoleted in the next
HP-UX release. This operation is only provided to main‐
tain backward compatibility for this release.
will remove the list of devices specified in devices from the
current dump
device list.
operation may also have the following flag set:
Changes to any of the lists will replace the current contents of
those lists. Without this flag, changes will add to the current
contents of those lists.
includeClasses is a bitmask of classes that must be dumped. If it is
set to all dumps will be full dumps. Other allowed values are
described under below.
excludeClasses is a bitmask of classes that may not be dumped unless a
full dump is required (due to the cause of the dump, or by explicit
operator request). If it is set to dumps will be disabled. Other
allowed values are described under below.
devices is an array of deviceCount pathnames of block or character
device files (legacy or persistent, see intro(7)) for crash dump
devices. To be valid, a device must be accessible and must not contain
a file system. Where LVM partitions are in use, the device number must
be for a partition, not the physical disk that contains it, and must
represent a partition that is strictly contiguous on the physical disk.
(LVM bad-block reallocation, and striping features may not be in use on
the partition.) Depending on the disk type, the dump space may be
restricted to the first 2 GB or 4 GB of the physical disk.
deviceReturn is an array of deviceCount integers for returning the
results of attempting to configure the corresponding device from the
devices array. Upon return, each element is set to a numeric value
indicating the result of configuring the corresponding device as fol‐
lows:
Successfully configured the corresponding device as a dump
device.
Failed to configure the corresponding device as a dump device.
The
absolute value of the returned number can be used as an
index into an array of error messages. The error mes‐
sage strings are defined in (see below).
The corresponding device has been configured but there is one or
more
notes or warnings associated with the device. The
returned value is a bitmap of warnings. The warning
message strings are defined in (see below).
Any parameters which are not used for the given operation should be set
to zero. Note that both devices and deviceReturn must be specified if
is specified.
Classes
The following system memory classes have been defined as of this writ‐
ing. Refer to the output of the command or to for definitions of any
classes added since publication. The memory page size is 4 Kb.
Unused physical memory pages
Kernel code pages
Buffer cache data pages
Kernel static data pages
Kernel dynamic data pages
File system metadata pages
User process stack pages
Unused Superpage pool pages
User process pages
Security Restrictions
The system call is restricted to processes owned by superusers or with
the privilege. See privileges(5) for more information about privileged
access on systems that support fine-grained privileges.
EXAMPLES
The following examples demonstrate the usage of
Example 1: Adding a Crash Dump Device
Example 2: Force Dumping of Buffer Cache
Example 3: Disable Dumps
Example 4: Using CCERR_STRINGS and CCWARN_STRINGS
Assume only one device, devices[0], is being added to the dump configu‐
ration. The following code will check the device_return[0] value and
print corresponding error or warning messages.
Example 5: Setting Compressed Dump ON, Excluding Unused Pages
Example 6: Marking Dump Device List Persistent
Example 7: Removing a Crash Dump Device
Example 8: Setting Concurrent Dump ON, Including Kernel Code Pages
RETURN VALUE
Successful completion.
Error.
is set to indicate the error.
If is set, indicates that at least one device has been configured but
one or more devices failed to configure. If is set, indicates
that at least one of the dump devices is not marked persistent.
ERRORS
fails if one or more of the following is true:
The calling process is not owned by superuser or not privileged.
operation does not have at least one of or set.
operation has both and set, and the same class (bit) is
specified in both includeClasses and exclude‐
Classes.
operation has both and set.
operation has both and set.
operation has set, and deviceCount is less than zero or
greater than
operation has both and set.
operation has both and set.
operation failed to save the configuration change.
operation failed to save the configuration change.
WARNINGS
On systems running VxVM 3.5, the swap volumes to be configured for sys‐
tem crash dumps should be created with the usage type as during the
creation of the swap volume. Not doing so will cause dump corruption.
It is also possible to use the option of the command to do the same
(see vxassist(1M)).
Marking dump devices using and will be obsoleted in the next HP-UX
release. operation of can be used to mark the dump device list as per‐
sistent.
SEE ALSOcrashconf(1M), vxassist(1M), pstat_getcrashdev(2), pstat_getcrash‐
info(2), alwaysdump(5), dontdump(5), dump_compress_on(5), dump_concur‐
rent_on(5), krs(5), privileges(5), intro(7).
crashconf(2)
