Subject: Re: backups
From: Scott Marlowe <smarlowe@g2switchworks.com>
To: "mcelroy, tim" <tim.mcelroy@bostonstock.com>
Cc: "'pgsql-admin@postgresql.org'" <pgsql-admin@postgresql.org>
In-Reply-To: <0C4841B42F87D51195BD00B0D020F5CB044B2643@MORPHEUS>
References: <0C4841B42F87D51195BD00B0D020F5CB044B2643@MORPHEUS>
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Date: Wed, 10 May 2006 11:11:53 -0500

On Wed, 2006-05-10 at 10:56, mcelroy, tim wrote:
> Thanks for the quick answer Scott.  I thought so but wanted to
> double-check.  I was asked by the person who performs our system
> backups if just backing up the directory where I put the nightly
> backups (created with pg_dump) was enough.  I also have them backing
> up /var/lib/pgsql and everything under that and they're complaining
> that it's taking too long.  I would think we would also want to back
> up the pg_xlog directory though.  Or is that overkill?  Is there a
> standard in the PG community I should follow?  Is just performing the
> pg_dump and saving that to tape enough?  I just don't want to get bit
> in the butt if I tell him to not back something up that should be
> backed up.

Generally speaking, backing up with pg_dump is plenty.

The /var/lib/pgsql directory backups aren't necessarily useful since the
files may not be backed up in the same "state"  i.e. some transaction
might be in two places at once, partially written, etc...  pg_dump
doesn't not have this problem.

If you want something more up to the second, look for point in time
replication in the postgresql docs.