How do I increase the size of my AIX dump device?

If you are receiving the following error in your AIX errpt, you need to increase the size of your dump device:

IDENTIFIER TIMESTAMP  T C RESOURCE_NAME  DESCRIPTION
E87EF1BE   0925150011 P O dumpcheck      The largest dump device is too small.

First, identify the largest dump device using the “/usr/lib/ras/dumpcheck -p” command, as in the following example:

eclipse:root:/# /usr/lib/ras/dumpcheck -p
The largest dump device is too small.

Largest dump device
         lg_dumplv
Largest dump device size in kb
         1048576
Current estimated dump size in kb
         1501593

In this example, the “dump device” that needs to be increased is “lg_dumplv”. If a file system needs to be increased, the output will give a “file system name”.

If a logical volume needs to be increased, review the current size of this logical volume using the lslv command, similar to the following example:

eclipse:root:/# lslv lg_dumplv
LOGICAL VOLUME:     lg_dumplv              VOLUME GROUP:   rootvg
LV IDENTIFIER:      0001c02b0000d60000000114a8a42e67.11 PERMISSION:     read/write
VG STATE:           active/complete        LV STATE:       opened/syncd
TYPE:               sysdump                WRITE VERIFY:   off
MAX LPs:            512                    PP SIZE:        128 megabyte(s)
COPIES:             1                      SCHED POLICY:   parallel
LPs:                8                      PPs:            8
STALE PPs:          0                      BB POLICY:      relocatable
INTER-POLICY:       minimum                RELOCATABLE:    yes
INTRA-POLICY:       middle                 UPPER BOUND:    32
MOUNT POINT:        N/A                    LABEL:          None
MIRROR WRITE CONSISTENCY: on/ACTIVE
EACH LP COPY ON A SEPARATE PV ?: yes
Serialize IO ?:     NO

Note the number of LPs, and increase the logical volume by a reasonable extent. In this example, I can double the size of the logical volume by adding an additional 8 LPs, as shown in the example command below:

eclipse:root:/# extendlv lg_dumplv 8

If a file system needs to be increased, review the current and estimated sizes of the file system provided by the dumpcheck utility. Then, expand the filesystem using a command similar to the following example:

chfs -a size=8G /var/adm/ras

Once you have confirmed the new size same lslv or df commands, run the same dumpcheck command to verify that no errors or warnings are generated. If the situation has been resolved, running the dumpcheck command will simply return you to the command prompt with no errors.

For more information on the AIX dump device, it’s purpose, and more detailed troubleshooting steps, see IBM’s website: Increase the Size of a Dump Device