Figure 3-7 Using Savecore; Avoiding Problems With Automatic Memory Dump - HP 9000 Series Service Manual

Troubleshooting
• There is not enough room in the dump device(s) or in the partition that savecore is
told to use. If the dump device is too small to contain the image of physical memory,
the dump will be only partially saved and may not be useful for troubleshooting a
specific problem.

Avoiding Problems with Automatic Memory Dump

The best way to avoid memory dump problems is to make sure your system is properly
set up. For example, make sure that the target directory for savecore has already been
created on your computer.
There are several ways to deal with the problem of the dump device or partition being
too small to contain the core files:
• You can modify /etc/rc.lod to specify an appropriately sized target directory for
savecore. The next time a core dump occurs, it will be saved to the new directory.
• Once a computer is down, you can specify a different target file system by booting the
system in single user mode and running the savecore manually.
• If your system has a large physical memory, you might want to use the -i option to
savecore. This option causes savecore to save as much important information as
possible after a system panic.
With the -i option, savecore saves the complete core file if there is enough space in the
target directory. If there is insufficient space in the target directory, savecore -i saves
the kernel pages and (if possible) user pages into a compressed core file. These
compressed core files are easier to transport. However, the analysis tools cannot be used
directly on compressed core files.
For more information on savecore and its options, see the entry for savecore (1M) in the
HP-UX Reference or the HP-UX man page. Also, see HP-UX System Tasks.
Running savecore Manually
The savecore command can be run manually. Typically, you enter a series of commands
like the following:

Figure 3-7 Using savecore

ISL> hpux -is
/* to boot single user after a crash */
/* (specify driver name and hardware address */
/* for the device you want to boot from) */
# /etc/fsck -p
/* to fix the file system */
# /etc/mount -a
/* to mount all disks (maybe "-a -t hfs") */
# /bin/df
/* to find where there is enough space */
# mkdir /var/adm/crash
/* assuming /tmp has enough space */
# cd /var/adm/crash
# /sbin/savecore.
/* to save the core file to the current directory */
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