crashconf(2)							System Calls Manual						      crashconf(2)

NAME

       crashconf() - configure system crash dumps

SYNOPSIS

DESCRIPTION

       changes the current system crash dump configuration.  The crash dump configuration consists of:

       o  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.

       o  The included class list.  This list identifies all system memory classes that must be included in any crash dump.

       o  The excluded class list.  This list identifies all system memory classes that should not be included in a crash dump.

       o  The compression mode selection.  This selection is used to turn compression or before dumping.

       o  The concurrency mode selection.  This selection is used to turn concurrency 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 regard-
       less 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 configuration 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 subse-
       quent call to Using the operation, the dump device list can be made persistent 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.   Marking  dump
		     devices using and will be obsoleted in the next HP-UX release.  This operation is only provided to maintain backward compati-
		     bility 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 message 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 writing.  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 privi-
       leged 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 configuration.  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 excludeClasses.

	      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 system 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 ALSO

       crashconf(1M),  vxassist(1M),  pstat_getcrashdev(2),  pstat_getcrashinfo(2),  alwaysdump(5), dontdump(5), dump_compress_on(5), dump_concur-
       rent_on(5), krs(5), privileges(5), intro(7).

																      crashconf(2)