From: | Josh Berkus <josh(at)agliodbs(dot)com> |
---|---|
To: | David Wheeler <david(at)kineticode(dot)com> |
Cc: | sfpug(at)postgresql(dot)org |
Subject: | Re: Transaction Log |
Date: | 2003-06-05 18:04:47 |
Message-ID: | 200306051104.47935.josh@agliodbs.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | sfpug |
David,
> > So, is there a postgresql.conf setting for the location of the WAL log
> > or something?
No, not yet. In 7.4, there will be a compile-time option for the location.
> Or do I just symlink $PGDATA/pg_xlog to the other disk?
You can symlink it, or mount it. I use the latter method:
1. Back up postgresql data and your file system.
2. Shut down postgresql
3. Create new partion on new disk
4. mount new partition at /tmp/xlog
5. copy all files from $PGDATA/xlog to /tmp/xlog
6. Edit your /etc/fstab to re-mount the partition at /tmp/xlog at $PGDATA/xlog
7. Reboot the system (have your RH Linux boot/install disks handy in case you
made a mistake editing /etc/fstab).
8. re-start Postgresql.
Of course, usually when I install a database I've already put PGDATA/xlog on a
seperate partition, so I don't have to go through the above.
Also, I've found that 3-disk RAID 5 gives about the worst data writing
performance on Postgresql of any disk configuation; about 1/3 the speed of
raw SCSI, worse if WAL is on the same array. Increasing the number of disks
... or switching to RAID 1+0 ... makes a large difference.
--
-Josh Berkus
Aglio Database Solutions
San Francisco
From | Date | Subject | |
---|---|---|---|
Next Message | David Wheeler | 2003-06-05 18:16:24 | Re: Transaction Log |
Previous Message | David Wheeler | 2003-06-05 17:39:27 | Re: Transaction Log |