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

HP-UX Handbook – Rev 13.00 Page 11 (of 38)
Chapter 08 Crash Dumps
October 29, 2013
local filesystem (by the rc command savecrash). In the case that the dump device is also the
primary swap, savecrash cannot run in the background because the swap area may be used
during further startup.
2) Were there any problems with savecrash (lack of space in the crash directory) you still have
the possibility to run it again after the system boot completed (-r Option for resave dump). In
case of a swap device there is a risk that parts of the dump are overwritten by "swapping"
activities and therefor unusable.
You can influence the interaction of savecrash/core and swapon in the config file of
savecrash/core. (see manpage of savecrash/core -w option)
Configuration steps
Creating the logical volumes that should be used for dump
You can specify up to 32 different dump devices. Each dump logical volume has to be
contiguous, i.e. all physical extents are placed one after another and reside on a single PV. Such
a LV can be created with the option -C y of lvcreate command. Bad block relocation must be
disabled (–r n):
# lvcreate -L <size in MB> -n <lvdump> -C y –r n /dev/<vgname>
Example:
# lvcreate -L <size in MB> -n lvdump -C y –r n /dev/vg00
You can check the LV parameters with lvdisplay:
# lvdisplay /dev/vg00/lvdump | grep Allocation
Allocation strict/contiguous
# lvdisplay /dev/vg00/lvdump | grep Bad
Bad block off
The dump LVs must not contain a filesystem of course.
Activating these logical volumes, i.e. tell the system to use them for dump
A traditional dump LV has to be located in the root VG (vg00) and the lvlnboot command is
used to tell the system to uses these LVs for dump. A reboot is neccessary in order to activate
them. Here’s how to configure such a dump device:
Display the current settings:
# lvlnboot -v
Boot Definitions for Volume Group /dev/vg00:
Physical Volumes belonging in Root Volume Group: