On 2009-12-02, at 20:41, John White wrote:> I wonder if lustre has a command akin to the GPFS `mmfsadm dump
> waiters` that basically shows any threads stuck in a holding pattern
> (for whatever reason, waiting on a lock, waiting on IO, etc) between
> clients and the server host cluster.
I guess that depends on how "akin" you mean. Lustre, in some sense,
has less need for such functionality because the DLM is not as
"distributed" as the GPFS one is. Lustre only ever has a single
server for any given set of resources - the MDT for inodes, and the
OSTs for their own objects. In contrast, GPFS locks migrate to the
clients and are "served" from there, which makes it a lot more complex
to debug.
It IS possible to dump the lock state of a server or client into the
lustre debug log, via "lctl set_param ldlm.dump_namespaces=1; lctl dk /
tmp/debug" but it may not be what you are looking for, since it will
only show that node''s lock state. I''ve never seen the output
of
"mmfsadm dump waiters", so I can''t comment on whether they
are at all
related.
Cheers, Andreas
--
Andreas Dilger
Sr. Staff Engineer, Lustre Group
Sun Microsystems of Canada, Inc.