Installation guide

raise the value so that the system writes crash dumps to secondary
partitions, issue the following command:
# sysconfig -r generic dump_sp_threshold=20480
In this exampe, the dump_sp_threshold attribute, which is in the
generic subsystem, is set to 20,480 512-byte blocks (40 MB). In this
example, the system attempts to leave the entire primary swap partition
completely open for system swapping. The system automatically writes the
crash dump to secondary swap partitions and the crash dump header to the
end of the primary swap partition.
The sysconfig command changes the value of system attributes for the
currently running kernel. To store the new value of the
dump_sp_threshold attribute in the sysconfigtab database, modify
that database using the sysconfigdb command. For information about
the sysconfigtab database and the sysconfigdb command, see the
sysconfigdb
(8) reference page.
_______________________ Note _______________________
Once the savecore program has copied the crash dump to a file,
all swap devices are immediately available for mounting and
swapping. The sharing of swap space only occurs for a short
time during boot, and usually on systems with a small amount
of physical memory.
13.6.4.2 Selecting and Using Noncompressed Crash Dumps
By default, crash dumps are compressed to save disk space, allowing you to
dump a larger crash dump file to a smaller partition. This can offer
significant advantages on systems with a large amount of physical memory,
particularly if you want to tune the system to discourage swapping for
realtime operations. On reboot after a crash, the crash dump utility,
savecore, automatically detects that the dump is compressed, using
information in the crash dump header in swap. It then copies the crash
dump file from swap to the /var/adm/crash directory. The compressed
crash dump files are identified by the letter z in the file name, to
distinguish them from noncompressed crash dump files. For example:
vmzcore.1.
Refer to the reference pages savecore
(8), expand_dump(8), and
sysconfig
(8) for information on crash dump compression and how to
produce a noncompressed crash dump file.
13–22 Administering Events and Errors