HP 9000 V2500 SCA, Operator'S Manual

Page: 163 / 206

Chapter 7 141
Recovering from failures
System panics
System panics
A system panic is the result of HP-UX encountering a condition that it is
unable to respond to and halting execution.
System panics are rare and are not always the result of a catastrophe.
They may occur on bootup, if the system was previously shut down
improperly. Sometimes they occur as a result of hardware failure.
Recovering from a system panic can be as simple as rebooting the
system. At worst, it may involve reinstalling HP-UX and restoring any
files that were lost or corrupted. If the system panic was caused by a
hardware failure such as a disk head crash, repairs have to be made
before reinstalling HP-UX or restoring lost files.
NOTE It is important to maintain an up-to-date backup of the files on the
system so that data can be recovered in the event of a disk head crash or
similar situation. How frequently the backups are updated depends on
how much data one can afford to be lose. For information on how to back
up data, refer to Managing Systems and Workgroups.
After HP-UX experiences a system panic, the system:
• May display an HPMC tombstone on the console if panic was caused
by an HPMC. A tombstone is a list of register values used for
troubleshooting.
• May attempt to save a core file (an image of physical memory) to the
dump device (by default this is the primary swap device).
• Attempts to reboot.
• Usually displays a panic message on the console. A panic message
consists of several lines of text starting with the heading System
Panic.
• May attempt to copy the core file to the file system (by default, to the
directory /tmp/syscore) if HP-UX can reboot.
Use the following procedure to troubleshoot a system panic:
Step 1. If an HPMC tombstone appears on the console, copy or print out the
“Machine Check Parameters” field, and all information that follows
them.