[Linux-cluster] GFS + DRBD Problems

[Lon Hohberger]

On Mon, 2008-03-03 at 11:23 +0000, gordan at bobich.net wrote:
> I have a 2-node cluster with Open Shared Root on GFS on DRBD.

Last week, I saw a car with a license plate from 'Wyoming'.  Now,
someone's running GFS on shared root DRBD.  My world's turning upside
down.


> A single 
> node mounts GFS OK and works, but after a while seems to just block for 
> disk. Very much as if it started trying to fence the other node and is 
> waiting for acknowledgement. 

If CMAN was trying to fence, you'd see it in /var/log/messages.  I'm not
sure about DRBD.


> There are no fence devices defined (so this 
> could be a possibility), 

Unlikely.  Even if this was the cause, you'd still see it (and you could
work around it).


> Unfortunately, it doesn't end there. When an attempt is made to dual-mount 
> the GFS file system before the secondary is fully up to date (but is 
> connected and syncing), the 2nd node to join notices an inconsistency, and 
> withdraws from the cluster. In the process, GFS gets corrupted, and the 
> only way to get it to mount again on either node is to repair it with 
> fsck.

Off the top of my head, this sounds like a DRBD thing.  If sync's
completed, it works, right?

-- Lon