Hp 9000 V2600 SCA Manual de usuario descargar pdf (Pagina 174)

152 Chapter 7

Recovering from failures

Abnormal system shutdowns

/etc/rc.config.d/savecrash) reduces system recovery time. After

the system recovery, run savecrash manually to copy the memory

image from the dump area to the HP-UX file system area.

Partial save

If a memory dump resides partially on dedicated dump devices and

partially on devices that are also used for paging, only those pages that

are endangered by paging activity can be saved.

Pages residing on the dedicated dump devices can remain there. It is

possible to analyze memory dumps directly from the dedicated dump

devices using a debugger that supports this feature. If, however, there is

a need to send the memory dump to someone else for analysis, move the

pages on the dedicated dump devices to the HP-UX file system area.

Then use a utility such as tar to bundle them for shipment. To do that,

use the command /usr/sbin/crashutil instead of savecrash to

complete the copy.

Crash information integrity

This section discusses how to make sure the part of memory that

contains the instruction or piece of data that caused the crash is

captured. The factors that must be considered are:

• Full dump vs. selective dump

• Dump definitions built into the kernel vs. defined at runtime

• Using a device for both paging and as a dump device

Full dump vs. selective dump

The only way to guarantee capturing the specific instruction or data that

caused the crash is to capture everything. This means selecting a full

dump of memory.

Be aware, however, that this can be costly in terms of time and disk

space. A large amount of time and disk space is needed to dump the

entire contents of memory in a system with a large memory

configuration or to copy a large memory image to the HP-UX file system

area during the reboot process.

The amount of dump area should at least be equal to the amount of

memory in the system; depending on a number of factors, additional disk

space greater than the amount of physical memory in the system may be

needed

1 2 ... 169 170 171 172 173 174 175 176 177 178 179 ... 205 206

Sin comentarios

Hp 9000 V2600 SCA Manual de usuario Pagina 174