On Mon, Mar 31, 2008 at 2:10 PM, Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > "Morris Goldstein" <morris.x.goldstein@xxxxxxxxx> writes: > > Suppose I have a database with $PGDATA on /dev/sda, and a tablespace > > directory on /dev/sdb. Will Postgres start successfully if /dev/sda is > > mounted and /dev/sdb is not? If not, why not? > > It will start, but you will have unpleasant failures when you try to use > tables in the secondary tablespace Understood. I can guarantee that there will be no such accesses until /dev/sdb is mounted. > ... note that if autovacuum is on, > that is likely to happen even without any explicit action on your part. That's a good point. We don't use autovacuum, and I guess we'd have to forego it. (Or can it be turned on and off dynamically?) But that makes me wonder: what about this sequence of events: - Postgres running normally on /dev/sda and /dev/sdb. - Update to table in /dev/sdb tablespace is committed but still exists in WAL. - Postgres crashes (e.g. power failure). - Postgres starts with /dev/sda only. - Recovery needs to update table in /dev/sdb tablespace. I assume bad things will happen in this case. Jack -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
