HP-UX Compressed Dump A.01.01 Release Notes

HP-UX Compressed Dump A.01.01 Release Note
What Is in This Version
Chapter 1 7
#define PS_EARLY_DUMP0x1 /* 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_COMPRESS0x8 /* Compress dump state */
The compression option is just a hint to the kernel to use the Compressed Dump feature.
During a system crash, the dump sub-system examines the state of the system and its
resources to determine whether it is possible to use compression. Depending on the resources
available, the system decides dynamically whether to dump compressed or not. A minimum of
five processors and more than 2GB of memory is required for the system to take a compressed
dump.
NOTE More than one crash may occur at the same time. In such cases, the dump
taken is uncompressed and the following message is displayed.
*** Dump defaulting to sequential without compression
*** Recursive Crash.
After a system crash, before dump starts, the dump type can be changed to compressed or
uncompressed from the console.
During compressed dump, dump progress is updated on the console every 15 seconds. When
savecrash (see the savecrash.1m manpage) runs during bootup, the dump is copied on to the
file system. savecrash copies compressed dump faster since the dump size is smaller
compared to uncompressed dump. The -p option, used with savecrash can be used to avoid
saving portions of the dump from dedicated dump devices. The -z option, used with
savecrash is ignored since the dump is already compressed. Specifying a chunk size lesser
than the size of memory belonging to one compression unit for compressed dump is also
ignored.
The Compressed Dump product uses a new crash dump format, PARDIR, for saving the
dumps. Existing versions of kernel dump debug tools do not support PARDIR format dumps.
To use with existing dump debug tools, the dump needs to be converted to any of the older
crash dump formats.
The following command converts crash.0 which is in PARDIR format into CRASHDIR
format in crash.1. The converted dump will take up considerably more disk space.
$ crashutil -v CRASHDIR /var/adm/crash/crash.0 /var/adm/crash/crash.1
The dump can also be converted in-place, using the following command:
$ crashutil -v CRASHDIR /var/adm/crash/crash.0