crashconf(1M) crashconf(1M)
NAME
crashconf - configure system crash dumps
SYNOPSIS
class]... cmode] pmode]... [device]...
DESCRIPTION
displays and/or 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.
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. Currently supported only on Integrity
systems.
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 faster and smaller dumps. If the dump is compressed, will also copy over the dump faster since the
dump will be smaller in size.
Since compressed dump requires additional processors and memory to do the compression, the system may fall back on uncompressed dump if it
could not identify the processing resources required to do compressed dump.
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.
Any changes to the configuration take effect immediately and remain in effect until the next system reboot, or until changed with a subse-
quent invocation of Using the option, changes to the include and exclude class lists and compression mode and concurrency mode can be made
persistent across system reboots, but the changes do not persist across kernel rebuilds. Use HP SMH (replacement for SAM) or (see sam(1M),
smh(1M), and kctune(1M)) to make tunables persistent. Changes to the dump device list can be made persistent across system reboots by
using the option.
device specifies a block or character device file name (legacy or persistent) of a device that is a valid destination for crash dumps. The
devices listed will be added to, deleted from (using or replaced (using in the current list of crash dump devices.
NOTE: A device has several device file names associated with it. These include the legacy device file names that correspond to the various
legacy paths to the device, and one persistent device file name that corresponds to the lun itself (see intro(7)).
The crash dump subsystem converts the legacy device file name to the persistent device file name prior to starting the configuration. The
crash dump subsystem will also use the block device file name for the configuration. Use the option to display the persistent device file
name. Display the corresponding legacy device file using (see ioscan(1M)).
The crash dump subsystem can choose any available path to the device for the configuration. Therefore, the configuration of the device may
not always be through the path represented by the legacy device file name. Use the option to display the lunpath hardware path (see
intro(7)) selected for the configuration.
class is the name (or number) of a system memory class which should be added to the appropriate class list. The list of system memory
classes can be obtained using The memory page size is 4 Kb.
class may also be the word in which case all classes are added to the appropriate list. (The effect of adding all classes to the included
class list is to force full crash dumps under all circumstances. The effect of adding all classes to the excluded class list is to disable
crash dumps.)
Persistent Dump Devices
To mark the dump devices as persistent, there are two configuration modes available. In this mode (this command) and (see crashconf(2))
are the only mechanisms available to mark dump devices as persistent. Logical volumes marked for dump using or and devices marked in for
dump will be ignored during boot-up. This is the preferred method for dump device configuration and will be used from this HP-UX release
onwards. This mode can be enabled using the option. VxVM stores extent information of persistent dump logical volumes in lif (see
lif(4)). Up to ten VxVM logical volumes can be marked persistent. The logical volumes which are not part of the root volume group cannot
be configured as persistent dump devices.
The logical volumes marked for dump using or and devices marked in for dump will be configured as dump devices during boot-up. Devices
marked as persistent, using will be ignored during boot-up. Marking devices using and will be obsoleted in the next HP-UX release. This
mode is deprecated in this release and will be obsoleted in the next HP-UX release. This is the default mode for dump and can be enabled
using the option also.
Persistent dump devices information is maintained in the kernel registry services, (KRS, see krs(5)).
Options
The following are valid options for
Apply the dump devices in
to the current list of crash dump devices:
o add these devices to the current list; or
o (with delete them from the current list; or
o (with replace the current list.
This is in addition to the dump devices specified on the command line. See fstab(4) for information on the format of
Specify the compression mode: either
or If the system is not able to identify enough processing resources to do compressed dump, a warning message will be issued.
Delete all dump devices mentioned on the command line from the current
list of crash dump devices. If the option is also specified, then dump devices in will also be deleted. However, the dump
device list cannot be made empty. This option cannot be used with the (replace) option.
Add the specified classes to
the list of excluded classes; or if is used, replace the list of excluded classes with the specified classes. If any of the
specified classes are present in the current included class list, they will be removed from the included class list.
Add the specified classes to the
the list of included classes; or if is used, replace the list of included classes with the specified classes. If any of the
specified classes are present in the current excluded class list, they will be removed from the excluded class list.
Display the lunpath hardware path (see
intro(7)) through which the device is currently configured. The lunpath hardware path is not displayed if the device is off-
line. This path may change in cases of path failover or device reconfiguration.
Switch dump configuration mode from
to This option will be obsoleted in the next HP-UX release. The and options are mutually exclusive. The extent information
for persistent VxVM dump logical volumes will continue to be present in lif (see lif(4)).
Specify the concurrency mode: either
or Depending on the availability of additional memory and the configuration of dump devices, the system may fall back to non-
concurrent dump mode and a warning message will be issued. Currently supported only on Integrity systems.
Specify that any changes should replace,
rather than add to, the current configuration. Thus, if devices or are specified, the current crash dump device list is
replaced with new contents. Likewise, with the and options replace the current class list. This option cannot be used with
the option.
Mark the dump device list as persistent across reboots.
This will also enable the Use to switch back to The and options are mutually exclusive.
When used with the
or options, set the dump tunables alwaysdump, dontdump, dump_compress_on, and dump_concurrent_on respectively, to make the
changes persistent across system reboots. The configuration file also controls the dump configuration. On rare occasions, the
system may crash before is run during the boot process. On those occasions, the configuration set using the dump tunables
alwaysdump, dontdump, dump_compress_on, and dump_concurrent_on will be used. Once the machine boots up, until the next invoca-
tion of or change of the dump tunables, the dump will follow the settings defined in the file.
Display the current crash dump configuration as well as the list of
persistent dump devices. If any changes to the current configuration are specified on the same command line as the configura-
tion will be displayed after the requested changes are made.
RETURN VALUE
Upon exit, returns the following values:
Success.
The requested configuration changes could not be made.
WARNINGS
If the dump device configured goes offline, then that device will not be used for taking a crash dump. output displays whether the dump
device is currently offline.
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 to create the swap volume
correctly.
When attributes of a VxVM dump logical volume change, it should be re-configured using the command so that crash dump will use the updated
values.
Marking dump devices using and will be obsoleted in the next HP-UX release. The option of can be used to mark the dump device list as per-
sistent.
The output of is not designed to be parsed by applications or scripts, but only to be read by humans. The output format may change without
notice. Applications which require crash dump configuration information should retrieve that information using
Dump devices created by must be contiguous option) with bad block relocation turned off option).
AUTHOR
was developed by HP.
SEE ALSO
ioscan(1M), kctune(1M), lvcreate(1M), sam(1M), smh(1M), vxassist(1M), crashconf(2), pstat(2), fstab(4), alwaysdump(5), dontdump(5),
dump_compress_on(5), dump_concurrent_on(5), krs(5), intro(7).
crashconf(1M)