[Pacemaker] DRBD and fencing

[Matthew Palmer]

On Wed, Mar 10, 2010 at 11:26:41AM -0000, Darren.Mansell at opengi.co.uk wrote:
> 
> On Wed, Mar 10, 2010 at 02:32:05PM +0800, Martin Aspeli wrote:
> > Florian Haas wrote:
> >> On 03/09/2010 06:07 AM, 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.
> >> *cringe* Which database is this?
> >
> > Postgres.
> >
> > Why are you cringing? From my reading, I had gathered this was a
> pretty
> > common setup to support failover of Postgres without the luxury of a
> > SAN. Are you saying it's a bad idea?
> 
> PgSQL on top of DRBD is OK.  PgSQL on top of OCFS2 is a disaster waiting
> to
> gnaw your leg off.
> 
> 
> --------------
> 
> Please forgive my ignorance, I seem to have missed the specifics about
> using OCFS2 on DRBD dual-primary but what are the main issues? How can
> you use PgSQL on dual-primary without OCFS2?

You don't.  Switch to single primary and let your cluster manager take care
of DRBD demote/promote and filesystem mounting.

- Matt