Re: Problem with PITR recovery

Simon Riggs wrote:
> On Mon, 2005-04-18 at 13:41 -0400, Bruce Momjian wrote:
> > Tom Lane wrote:
> > > Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us> writes:
> > > > I guess I didn't see the connection between the file system backup and
> > > > the WAL files, when in fact you need the WAL files that go with the file
> > > > system badckup to do the recovery. Do you have new suggested text?
> > >
> > > I think it probably needs to mention *both* the tar dump and the WAL
> > > segment file(s). I can take a whack at it if you like.
> >
> > I modified the sentence to say:
> >
> > Once you have safely archived the file system backup and the WAL segment
> > files used during the backup (as specified in the backup history file),
> > you can delete all archived WAL segments with names numerically less.
> >
> > Feel free to whack it a second time.
>
> whack...
>
> ...you can delete all archived WAL segments with names numerically
> less.
>
> but I'm not sure it's best practice to delete them at that point. I
> would recommend that users keep at least the last 3 backups. So, I'd
> prefer the wording
>
> ...all archived WAL segments with names numerically less will no longer
> be needed as part of that backup set. You may delete them at that point,
> though you should consider keeping more than one backup set to be
> absolutely certain that you are can recover your data.

OK, new wording:

Once you have safely archived the file system backup and the WAL segment
files used during the backup (as specified in the backup history file),
all archived WAL segments with names numerically less are no longer
needed to recover the file system backup and may be deleted. However,
you should consider keeping several backup sets to be absolutely certain
that you are can recover your data. Keep in mind that only completed WAL
segment files are archived, so there will be delay between running
<function>pg_stop_backup</> and the archiving of all WAL segment files
needed to make the file system backup consistent.

--
Bruce Momjian | http://candle.pha.pa.us
pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073