Abnormal system shutdowns, Fast dump – HP 9000 V2600 SCA User Manual

Page 169

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Chapter 7

147

Recovering from failures

Abnormal system shutdowns

Abnormal system shutdowns

Abnormal systems shutdowns (often referred to as system crashes) can
occur for many reasons. In some cases, the cause of the crash can be
easily determined. In some extreme cases, however, it may be necessary
to analyze a snapshot (called a core dump or simply dump) of the
computer’s memory in order to determine the cause of the crash. This
may require the services of the Hewlett-Packard Response Center.

V-Class servers using HP-UX Release 11.0 or greater employ a more
efficient dump mechanism than other HP servers using previous releases
of HP-UX. This mechanism is called fast dump.

Fast dump

When a system crashes, the operator can now choose whether or not to
dump, and if so, whether the dump should contain the relevant subset of
memory or all memory (without operator interaction).

By default fast dump selectively dumps only the parts of memory that
are expected to be useful in debugging. It improves system availability in
terms of both the time and space needed to dump and analyze a large
memory system.

The following commands allow the operator to configure, save, and
manipulate the fast core dump:

crashconf

—Configures the destination and contents of a crash

dump without rebooting. See the crashconf(1M) man page for more
information.

savecrash

—Runs at boot time and saves any information that may

be overwritten by normal system activity. See the savecrash(1M) man
page for more information.

crashutil

—Saves or manipulates the crash dump (if desired). It can

format the dump snapshot so that it can be read by the older
commands. See the crashutil(1M) man page for more information.

Installations that used to call

savecore

in any way other than by the

HP-supplied, unmodified

/sbin/init.d/savecore

script need to be

updated to use

savecrash

and/or

crashutil

.

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