Compressed Dump

Compressed Dump White Paper, Version 1.3
page 9
crashconf(2) crashconf(2)
NAME
crashconf() - configure system crash dumps
SYNOPSIS
#include <sys/crashconf.h>
int crashconf(
int operation,
int includeClasses,
int excludeClasses,
int deviceCount,
char **devices,
int *deviceReturn
);
DESCRIPTION
crashconf() 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 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 smaller and faster dumps. Copying of
compressed dump from the dump device over to the filesystem will also be faster
using savecrash(1M).
Since compressed dump requires additional processors and memory to do the com-
pression, 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.