Serge Dubrouski wrote:
On Wed, Mar 10, 2010 at 5:30 PM, Martin Aspeli<optilude+li...@gmail.com> wrote:
Martin Aspeli wrote:
Hi folks,
Let's say have a two-node cluster with DRBD and OCFS2, with a database
server that's supposed to be active on one node at a time, using the
OCFS2 partition for its data store.
If we detect a failure on the active node and fail the database over to
the other node, we need to fence off the shared storage in case the
active node is still writing to it.
Can this be done in such a way that the local DRBD/OCFS2 refuses to
accept writes from the now-presumed-dead node? I guess this would be
similar to putting an access rule on a SAN to block off the previously
active node from attempting to read or write any data.
Is this feasible?
We went off on a side-track, I think, but I'd still like to know the answer:
Can one "fence" at the DRBD level?
From the thread, it sounds like we'll not use OCFS2 for the Postgres data
store, but would still use DRBD, e.g. with ext4 or whatever. The fencing
problem would then be equally, if not more, acute.
It's basically between doing something at the DRBD level, if that's
feasible, or using the DRAC IPMI device on our server to shoot it.
But if you implement fencing on Pacemaker level and include your
DRBD/Filesystem resource into Pacemaker configuration you'll be fine.
Sorry, I don't quite understand what you mean.
What would "fencing on the Pacemaker level" look like? Certainly, DRBD
would be managed by the cluster.
Martin
_______________________________________________
Pacemaker mailing list
Pacemaker@oss.clusterlabs.org
http://oss.clusterlabs.org/mailman/listinfo/pacemaker
