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Dump order, What happens when the system crashes – HP 9000 V2600 SCA User Manual

Page 182

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Chapter 7

Recovering from failures

Abnormal system shutdowns

To have

crashconf

add the devices represented by the block device files

/dev/dsk/c0t1d0

and

/dev/dsk/c1t4d0

to the dump device list,

enter the following:

/sbin/crashconf /dev/dsk/c0t1d0/dev/dsk/c1t4d0

To have

crashconf

replace any existing dump device definitions with

the logical volume

/dev/vg00/lvol3

and the device represented by

block device file

/dev/dsk/c0t1d0

, enter the following:

/sbin/crashconf -r /dev/vg00/lvol3 /dev/dsk/c0t1d0

Dump order

The order that devices dump after a system crash is important when
using the primary paging device along with other devices as a dump
device.

Regardless of how the list of currently active dump devices was built
(from a kernel build, from the

/etc/fstab

file, from use of the

crashconf

command, or any combination of the these) dump devices are

used (dumped to) in the reverse order from which they were defined. The
last dump device in the list is the first one used, and the first device in
the list is the last one used.

Place devices that are used for both paging and dumping early in the list
of dump devices so that other dump devices are used first and
overwriting of dump information due to paging activity is minimized.

What happens when the system crashes?

This section discusses the unlikely event of a V-Class system crash. A
system panic means that HP-UX encountered a condition that it could
not to handle. Sometimes the cause of the crash is apparent, but many
times an in-depth analysis is required. HP-UX is equipped with a dump
procedure to capture the contents of memory at the time of the crash.

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