[Linux-cluster] lock_dlm: gdlm_cancel messages?

[David Teigland]

On Tue, Sep 02, 2008 at 03:11:35PM -0700, Edward Muller wrote:
> We have a customer who we believe is putting excessive locking  
> pressure on one of several gfs volumes (9 total across 5 systems).
> 
> They've started to get occasional load spikes that seem to show that  
> the gfs is "locking" for a minute or two. Without any action on our  
> part the load spikes clear and everything continues as normal.
> 
> And we've recently seen the following log entries:
> 
> Sep  2 12:57:57 xc88-s00007 kernel: lock_dlm: gdlm_cancel 1,2 flags 0
> Sep  2 12:57:57 xc88-s00007 kernel: lock_dlm: gdlm_cancel skip 1,2  
> flags 0
> Sep  2 12:57:58 xc88-s00007 kernel: lock_dlm: gdlm_cancel 1,2 flags 0
> Sep  2 12:57:58 xc88-s00007 kernel: lock_dlm: gdlm_cancel skip 1,2  
> flags 0
> Sep  2 12:58:40 xc88-s00007 kernel: lock_dlm: gdlm_cancel 1,2 flags 0
> Sep  2 12:58:40 xc88-s00007 kernel: lock_dlm: gdlm_cancel skip 1,2  
> flags 0
> Sep  2 12:58:58 xc88-s00007 kernel: lock_dlm: gdlm_cancel 1,2 flags 0
> Sep  2 12:58:58 xc88-s00007 kernel: lock_dlm: gdlm_cancel skip 1,2  
> flags 0
> Sep  2 12:59:14 xc88-s00007 kernel: lock_dlm: gdlm_cancel 1,2 flags 0
> Sep  2 12:59:14 xc88-s00007 kernel: lock_dlm: gdlm_cancel skip 1,2  
> flags 0

FS activity will block while gfs does recovery, and the cancel messages
are also usually due to recovery.  If gfs is doing recovery, you'd see
clear messages about it in /var/log/messages.  Otherwise, I'd check
whether they're using any gfs administrative commands like gfs_tool.

Dave