On Wed, Jul 30, 2003 at 01:55:00AM +0530, Rajesh Kumar Mallah wrote:
> >One possibility is to run postgresql (regular postgresql - no patches
> >required) controlled by heartbeat (http://www.linux-ha.org/) on two
> >nodes. Heartbeat will then make sure that only one of the nodes are
> >active at any time.
> >
> >You will have to put the databases on shared storage; either something
> >like a shared SCSI RAID, or a software replication device like drdb or
> >md+nbd.
>
> I think it has been pointed out many times in the list
> the running postgresql on a shared storage is dangerous.
Running _any_ application on shared storage requires meassures to make
sure the data is not corrupted. And yes, it is dangerous unless
you get it right.
Bascily the problem is that is you are not careful both nodes can
start postgresql at once, and they _will_ corrupt the database.
The HA-software (like heartbeat) and the fencing-software (like
stonith) will take care of this, making it safe.
--
Ragnar Kjorstad
