Re: Query plan looks OK, but slow I/O - settings advice?
От | Jeffrey W. Baker |
---|---|
Тема | Re: Query plan looks OK, but slow I/O - settings advice? |
Дата | |
Msg-id | 1124434535.3257.7.camel@noodles обсуждение исходный текст |
Ответ на | Query plan looks OK, but slow I/O - settings advice? ("Roger Hand" <RHand@kailea.com>) |
Ответы |
Re: Query plan looks OK, but slow I/O - settings advice?
|
Список | pgsql-performance |
On Tue, 2005-08-16 at 10:46 -0700, Roger Hand wrote: > The disks are ext3 with journalling type of ordered, but this was later changed to writeback with no apparent change inspeed. > > They're on a Dell poweredge 6650 with LSI raid card, setup as follows: > 4 disks raid 10 for indexes (145GB) - sdc1 > 6 disks raid 10 for data (220GB) - sdd1 > 2 mirrored disks for logs - sdb1 > > stripe size is 32k > cache policy: cached io (am told the controller has bbu) > write policy: write-back > read policy: readahead I assume you are using Linux 2.6. Have you considered booting your machine with elevator=deadline? You can also change this at runtime using sysfs. These read speeds are not too impressive. Perhaps this is a slow controller. Alternately you might need bigger CPUs. There's a lot of possibilities, obviously :) I'd start with the elevator, since that's easily tested. -jwb
В списке pgsql-performance по дате отправления: