Ext3 users - Mar 2004 - stalled 'sync' on ext3+quota over drbd

I don't know yet if this is an ext3, quota or drbd issue, but I'll ask
anyway.  I am building a HA NFS server using two Dell-1750's and drbd. 
I have ext3 filesystem with quota built on drbd device running over
200Gb disk partition (hardware raid0+1), drdb-mirrored across servers. 
The kernel is 2.4.25, so hopefully quota deadlock should not be a
problem (it was on 2.4.24).

Now, the setup mostly works fine.  But if you actively use the
filesystem for some time (hour of copying a large tree over NFS), then
then try 'sync' command, the latter runs very long (10 minutes or more),
eating 99% CPU according to top, and the system becomes very sluggish
(leading to stalled replication, heartbeat misbehavior) and in fact
unusable.

Any ideas why this happens and/or suggestions for further investigation?

Eugene
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Hi,

On Wed, 2004-03-24 at 10:47, Eugene Crosser wrote:
> Now, the setup mostly works fine.  But if you actively use the
> filesystem for some time (hour of copying a large tree over NFS), then
> then try 'sync' command, the latter runs very long (10 minutes or
more),
> eating 99% CPU according to top, and the system becomes very sluggish
> (leading to stalled replication, heartbeat misbehavior) and in fact
> unusable.
You'd need to try capturing a profile of the 99% cpu loop for us to be
able to investigate this any further.

Cheers,
 Stephen