Compressed Dump

Compressed Dump White Paper, Version 1.3

page 5

crashconf(1M) crashconf(1M)

NAME

crashconf - conﬁgure system crash dumps

SYNOPSIS

/sbin/crashconf [-artv] [-i|-e class] [-c mode]...[device...]

DESCRIPTION

crashconf displays and/or 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 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 compression ON

or OFF, 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 ON will result in faster and smaller dumps. If the dump is

compressed, savecrash 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 com-

pression, the system may fall back on uncompressed dump if it could not identify the

processing resources required to do compressed dump.

Any changes to the conﬁguration take effect immediately and remain in effect until

the next system reboot, or until changed with a subsequent invocation of crashconf.

Using the option -t, changes to the include and exclude class lists and compression

mode can be made persistent across system reboots. But the changes to not persist

across kernel rebuilds. Use SAM or kctune(1M) to do this.

device speciﬁes a block device ﬁle name of a device that is a valid destination for

crash dumps. All such devices listed on the command line will be added to the end

of the current list of crash dump devices, or will replace the current list of crash

dump devices, depending on whether -r is speciﬁed.