Alan Hodgson wrote:
On Wednesday 18 June 2008, Craig Ringer <craig@xxxxxxxxxxxxxxxxxxxxx> wrote:
Every file from /var/lib/pgsql/ before I started this is on the
weekly backup tape from last Friday night. If need be I can restore
from that and start over.
Well, no worries then. I'm sure you can understand that for many people
- way TOO many people - that is not the case, so it's well worth
stressing the point.
If the database was in use when _that_ backup was taken, it may also not be
usable.
You can't just backup a live database from the filesystem level and expect
it to work ...
It should be OK, if less than ideal, if:
- You have fsync enabled (which you do if you care about your data); and
- Your filesystem supports consistent snapshots
If you can take a point-in-time snapshot at the filesystem level and
copy that, it should be OK. Pg will still have to do a bunch of work
when started up off the restored data, though.
It makes much more sense to just warn Pg about the copy about to be
taken, or use pg_dump . Any decent backup system will provide hooks to
run pre- and post- scripts to do this sort of thing.
--
Craig Ringer
