Installation guide

Saving Memory Dumps
5-42 Fault Tolerant System Administration (R1004H) HP-UX version 11.00.03
thus, enhances system availability. (Selective save_mcore also supports a 64
bit kernel and dumps on systems with a greater than 4 GB memory size.)
By default, save_mcore will attempt to save a dump to the file system you
have specified in the file /etc/rc.config.d/savecrash, except in the
following instances:
–You changed the save_mcore_dumps_only=1 (the default) parameter
in the conf file to save_mcore_dumps_only=0. Doing this indicates
that you want all dumps to be handled by the HP utility, savecrash.
– The system was not in duplexed mode when the panic occurred. If a crash
occurs when the system is in simplexed mode, savecrash is called as the
dump utility instead of save_mcore.
■ savecrash—The typical sequence that occurs when savecrash is used as
the dump utility is as follows: when a panic occurs, the system busses are
scanned and the physical memory (or portions of if) are written to a dump
device and then, after the system is rebooted, savecrash extracts the dump
from the dump space and moves it to /var/adm/crash in the HP-UX file
system (to the location you specified in (/etc/rc.config.d/savecrash)
for later examination.
Dump Configuration Decisions and Dump
Space Issues
If you decide to use savecrash as the default dump utility, or to prevent problems
if a dump occurs while the system is in simplex mode (and savecrash is
automatically used to capture the dump), you must consider how you will
configure system dumps. For general guidelines for determining your dump space
needs, refer to Managing Systems and Workgroups (B2355-90157).
Also, you must determine how much dump space you will need, so that you can
define sufficient, but not excessive, dump space to hold the dump. It is essential
that you have adequate space in dump and in /var/adm/crash (or any other
dump-space location in the HP-UX file system (that you specified in
/etc/rc.config.d/savecrash. In general, you should consider the criteria in
Table 5-10 when deciding how to configure your system dumps.