How to Collect a GPFS snap

Question:

How do I collect a gpfs snap for review by  IBM GPFS support?

Answer

The command to collect GPFS Snap is  "gpfs,snap" , this is very generic but very helpful.

# gpfs.snap

Note:  The  purpose of above command is to collect the  snap on one node in the cluster,preferably the problematic one.

If the cluster is experiencing problems as a whole use -a flag

# gpfs.snap -a

Note1:  -a flag only recommended for smaller clusters as it collects the logs for all of the nodes in the cluster.

Note2: -d  option can  specify the Output Directory but  the default is /tmp/gpfs.snapOut.

==> Another recommendation is collect an mmfsadm dump waiters

/usr/lpp/mmfs/bin/mmfsadm dump waiters > gpfs.waiters
/usr/lpp/mmfs/bin/mmfsadm dump all > gpfs.dump.all
/usr/lpp/mmfs/bin/mmfsadm dump kthreads > gpfs.dump.kthreads

==> Another file you need to check is log file /var/adm/ras/mmfs.log.latest

This information will greatly assist development in reviewing performance or problematic issues in GPFS.