Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Administering a System: Booting and Shutdown
Abnormal System Shutdowns
Chapter 5538
You can disable compression by using the crashconf -c command with the off
argument, as follows:
$ crashconf -v -c off
{Lines omitted from display}
Dump compressed: OFF
Any changes that you make to the dump configuration take effect immediately
but will persist only until the next reboot or the next invocation of the crashconf
command. To make changes persist across reboots, use the -t option. To make
changes persist across kernel rebuilds, use SAM or the kctune command.
In HP-UX 11i v2, you can use the persistent dynamic tunable dump_compress_on
to set compression on or off as required. Set this tunable by using the crashconf
command with the -t option.
Prior to HP-UX 11i v2, you can also edit the /etc/rc.config.d/crashconf
initialization script to set the compression option for every subsequent reboot.
Open this file with a text editor and modify the value of the
CRASHCONF_COMPRESS variable to 1 (enable, on) or 0 (disable, off). If the
CRASHCONF_COMPRESS variable does not exist in /etc/rc.config.d/crashconf,
the default behavior is to compress the dump. Beginning with HP-UX 11i v2, this
configuration is handled by the dynamic tunable dump_compress_on, and is not
controlled by crashconf.
Programs can use the pstat_getcrashinfo() function to query the current
crash dump configuration. See pstat (2) for more information. The psc_flags
data field shows whether dump compression is enabled or not. For example:
/*
* This structure describes the system crash dump configuration.
* It is only available as 64-bit data (_PSTAT64 defined).
*/
struct pst_crashinfo {
int64_t psc_flags; /* Dump config. flags, see below */
struct __psdev psc_headerdev; /* Device containing dump header */
int64_t psc_headeroffset;/* Byte Offset of dump hdr on device */
int64_t psc_ncrashdevs; /* Number of dump devices */
int64_t psc_totalsize; /*Total amount of dump space (kB) */
int64_t psc_included; /* Page classes to be included */
int64_t psc_excluded; /* Page classes to be excluded */
int64_t psc_default; /*Defaults for unspec’d classes*/
int64_t psc_nclasses; /* Number of classes */
int64_t psc_pgcount[PST_MAXCLASSES]; /* Number of pages in each class *
/
int64_t psc_reserved; /* Reserved for future use */
};
/* Flag values for psc_flags: */
#define PS_EARLY_DUMP 0x1 /* An early dump was taken */
#define PS_CONF_CHANGED 0x2 /* Config. changed since boot */
#define PS_HEADER_VALID 0x4 /* headerdev and headeroffset valid */
#define PS_COMPRESS 0x8 /* Compress dump state*/