With the increase in the number of disks that we can afford to have in 1 box..we will definitely plan on having WAL on dedicated disks. Previously..we were stuck with the chassis limitation of 6 disks per box. On Thu, Apr 29, 2010 at 12:25 PM, Scott Marlowe <scott.marlowe@xxxxxxxxx> wrote: > On Thu, Apr 29, 2010 at 11:26 AM, Anj Adu <fotographs@xxxxxxxxx> wrote: >> All the disks are usually laid out in a single RAID 10 stripe . There >> are no dedicated disks for the OS/WAL as storage is a premium > > You should at least investigate the performance difference of having a > separate volume for WAL files on your system. Since WAL files are > mostly sequential, and db access is generally random, the WAL files > can run really quickly on a volume that does nothing else but handle > WAL writes sequentially. Given the volume you're handling, I would > expect that storage is not any more important than performance. > > The fact that you're asking whether to go with 12 or 24 600G disks > shows that you're willing to give up a little storage for performance. > I would bet that the 24 10k disks with one pair dedicated for OS / > pg_xlog would be noticeably faster than any single large volume config > you'd care to test, especially for lots of active connections. > -- Sent via pgsql-admin mailing list (pgsql-admin@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-admin
