Running Savecore Manually - HP 3000 Series Handbook

For HP Internal Use Only
• You can modify jetcjrc 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:
ISL> hpux -is
#
/etc/fsck -p
#
/etc/mount -a
#
/bin/df
#
mkdir /tmp/syscore
#
cd /tmp/syscore
#
/etc/savecore
I*
to boot single user after a crash
*I
I*
(specify driver name and hardvare address
*I
I*
for the device you want to boot from)
*I
'*
to fix the file system
*I
'* to mount all disks (maybe 11 -a -t hfs 11
)
*'
'* to find where there is enough space
*'
'* assuming /tmp has enough space
*I
'*
to save the core file to the current directory
*I
If the system is configured with the primary swap device as the dump device (default
configuration), a problem can occur if savecore is run after the system has been brought up
multi-user. Once the system starts back up, it is free to start swapping over the swap device.
This could corrupt a crash image written out to the swap device.
If the dump device is configured to use another logical volume or file system rather than the
primary swap device, the system's physical memory image remains intact; you can savecore
after the system has been brought up to multi-user mode. At this point, you can mount a
magnetic tape and use the -t option to savecore to save the system's physical memory image
to magnetic tape.
5-28 Troubleshooting