Re: [ADMIN] Backup

[Chander Ganesan <chander(at)otg-nc(dot)com>]

Magnus Hagander wrote:
> On Thu, Jan 31, 2008 at 03:34:05PM +0100, Martijn van Oosterhout wrote:
>   
> > On Thu, Jan 31, 2008 at 01:28:48PM +0000, Simon Riggs wrote:
> >     
> > > That sentence has no place in any discussion about "backup" because the
> > > risk is not just a few transactions, it is a corrupt and inconsistent
> > > database from which both old and new data would be inaccessible.
> > >       
> > Hmm? I thought the whole point of a filesystem snapshot was that it's
> > the same as if the system crashed. And I was fairly sure we could
> > recover from that...
> >     
>
> That was my assumption as well. *Assuming* that the filesystem snapshot is
> consistent. There are a bunch of solutions that don't do consistent
> snapshots between different partitions, so if your WAL or one tablespace is
> on a different partition, you'll get corruption anyway... (seen this in
> Big Commercial Database, so that's not a pg problem)
>   
Agreed.  That's why I made it a point to mention that all of your 
tablespaces should be on the same file system...  In hindsight, I should 
have also stated that your WAL logs should be on the same file system as 
well...

--
Chander Ganesan
Open Technology Group, Inc.
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Morrisville, NC  27560
919-463-0999/877-258-8987
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