[Linux-cluster] Re: problems with 8 node production gfs cluster

[David Teigland]

On Mon, Apr 17, 2006 at 05:41:39PM +0200, Nemanja Miletic wrote:
> Hi,
> 
> Does anyone think that turning on journaling on files could help us
> speed up the access to gfs partition?
> 
> This would be difficult because journaling can be turned on only on
> files that are empty. We have a large number of empty files of active
> users that download all their mail from pop3 server, so turning on
> jurnaling for them should be possible. 

Data journaling might help, it will speed up fsync(), but will increase
the i/o going to your storage.

> What size should be the journals when file journaling is on?

Continue to use the default.

Another thing you might try is disabling the drop-locks callback, allowing
GFS to cache more locks.  Do this before you mount:
  echo "0" >> /proc/cluster/lock_dlm/drop_count

Dave