Re: Install Postgres on a SAN volume?

On Tue, 9 Sep 2008, Magnus Hagander wrote:

> As long as your SAN guarantees an atomic snapshot of all your data
> (which every SAN I've ever heard of guarantees if you're on a single
> volume - entry level SANs often don't have the functionality to do
> multi-volume atomic snapshots, though), you don't need to set up PITR
> for simple backups

It's all those ifs in there that leave me still recommending it.  It's
certainly possible to get a consistant snapshot with the right hardware
and setup.  What concerns me about recommending that without a long list
of caveats is the kinds of corruption you'd get if all those conditions
aren't perfect will of course not ever happen during testing.  Murphy says
that it will happen only when you find yourself really needing that
snapshot to work one day.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD