HP-UX System Administrator's Guide: Overview

While the dump is in occurring, status messages on the system console indicate the
dump’s progress.
IMPORTANT: You can interrupt the dump at any time by pressing the ESC (escape)
key. It can take as long as 15 seconds to abort.
If you interrupt a dump, it will be as though a dump never occurred; that is, you will
not get a partial dump.
Following the dump, the system attempts to reboot.
The Reboot
After the dumping of physical memory pages is complete, the system attempts to reboot
(if the AUTOBOOT flag is set). For information on the AUTOBOOT flag, see HP-UX System
Administrator’s Guide: Routine Management Tasks.
The savecrash Processing Option
You can define whether or not you want a process called savecrash to run as your
system boots. This process copies (and optionally compresses) the memory image
stored on the dump devices to the HP-UX file system area. Space permitting, you can
store multiple crash dumps in the file system area in case there is more than one panic
event. If you do not run savecrash during or shortly after boot, you risk only having
the latest dump available, on the dump devices.
Dual-Mode Devices (dump / swap)
By default, savecrash is enabled and performs its copy during the boot process. You
can disable this operation by editing the /etc/rc.config.d/savecrash file, setting
the SAVECRASH environment variable to a value of 0. This is generally safe to do if
your dump devices are not also being used as paging devices.
From the savecrash(1M) manpage:
• “If there is insufficient space in the file system for the portions of the crash dump
that need to be saved, savecrash will save as much as will fit in the available
space. (Priority is given to the index file, then to the kernel module files, and then
to the physical memory image.) The dump will be considered saved, and
savecrash will not attempt to save it again, unless there was insufficient space
for any of the physical memory image. (See the description of option -r.)”
The -r option to savecrash allows you to resave a crash that has already been marked
as saved. If a save fails (or if only a partial save was made) due to lack of file system
space, you have a chance, once the system is running again, to clean up the file system
Start-up and Shutdown 105