Managing Systems and Workgroups: A Guide for HP-UX System Administrators

Administering a System: Booting and Shutdown
Abnormal System Shutdowns
Chapter 5534
Systems Running HP-UX Releases Prior to Release 11.0
Prior to HP-UX Release 11.0, you have limited control over the dump
process. You can control:
• Whether or not a dump occurs (you can define the dump devices in
the kernel file to be dump none to prevent dumps from occurring)
• Which devices will be used as dump devices
• Whether or not the savecore command runs at reboot time to copy
the dumped memory image to the HP-UX file system area
NOTE You must define the dump devices for your system when you build its
kernel. See “Kernel Dump Device Definitions” on page 544 for details on
how to do this. And, if you want to change the dump devices, you need to
build a new kernel file and boot to it for the changes to take effect.
Dump Configuration Decisions
As computers continue to grow in speed and processing power, they also
tend to grow in physical memory size. Where once a system with 16MB of
memory was considered to be a huge system, today it is barely adequate
for most tasks. Some of today’s HP-UX systems can have terabytes of
memory. This is important to mention here because the larger the size of
your computer’s physical memory, the longer it will take to dump its
contents to disk following a system crash (and the more disk space it will
consume).
Usually, when your system crashes it is important to get it back up and
running as fast as possible. If your computer has a very large amount of
memory, the time it takes to dump that memory to disk might be
unacceptably long when you are trying to get the system back up quickly.
And, if you happen to already know why the computer crashed (for
example, if somebody accidently disconnected the wrong cable), there’s
little or no need for a dump anyway.
Prior to HP-UX Release 11.0, you have little control over the process. You
must decide in advance whether or not you want a dump to occur when
the system crashes, and you must build that decision into the kernel
itself. However, beginning with HP-UX Release 11.0, a new runtime