HP-UX HB v13.00 Ch-08 - Crash Dumps

HP-UX Handbook – Rev 13.00 Page 16 (of 38)
Chapter 08 Crash Dumps
October 29, 2013
CLASS PAGES INCLUDED IN DUMP DESCRIPTION
-------- ---------- ---------------- ------------------------------
UNUSED 3645411 no, by default unused pages
USERPG 7113 no, by default user process pages
BCACHE 210990 no, by default buffer cache pages
KCODE 2670 no, by default kernel code pages
USTACK 264 yes, by default user process stacks
FSDATA 116 yes, by default file system metadata
KDDATA 68736 yes, by default kernel dynamic data
KSDATA 259004 yes, by default kernel static data
Total pages on system: 4194304
Total pages included in dump: 328120
Dump compressed: ON
DEVICE OFFSET(kB) SIZE (kB) LOGICAL VOL. NAME
------------ ---------- ---------- ------------ -----------------
31:0x03a000 310112 4194304 64:0x000002 /dev/vg00/lvol2
----------
4194304
If you like to make the configuration changes either for selective dump or for compressed dumps
resistant across reboots you need to modify the rc-script /etc/rc.config.d/crashconf.
Usually there should be no need to change the defaults.
The compressed dump feature uses a new crash dump format, PARDIR, for saving the dumps.
You recognize a compressed dump with these evidences:
 In the INDEX file you will find a version 5.
 In the dump directory you will find indexX.Y files along with the usual image.X.Y files.
The dumpreading tools (p4, crashinfo, kmeminfo, etc...) are aware of this new format.
Since the dump is compressed you have little gain to compress it again with gzip, yet since the
compression is done with a 'compress(1)' compatible algorithm and small chunks, gzip'ing the
dump still reduce it a bit sometime.
A consequence of the compressed dump is indeed a faster ”time to dump” and a somewhat faster
“time to reboot” but the dumpreading tools suffer a serious performance penalty, making the
“time to diagnose” or “time to fix” significantly longer.
NOTE: To enable compressed dump feature at UX 11.11 you need to install the CDUMP11i
product from http://www.software.hp.com/ER_products_list.html. This product contains a set of
enabling patches. At UX 11.23 the compressed dump feature is enabled in core, hence no
product or patches are needed.
Documentation about the compressed dump feature can be found at in the “Managing Systems
and Workgroups” paper at
http://www.docs.hp.com/hpux/os/11i/index.html#System%20Administration