On Tue, Feb 24, 2009 at 5:21 PM, Jordan Tomkinson <jor...@moodle.com> wrote: > > On Wed, Feb 25, 2009 at 12:05 AM, Aidan Van Dyk <ai...@highrise.ca> wrote: >> >> * Greg Smith <gsm...@gregsmith.com> [090201 00:00]: >> >> > Shouldn't someone have ranted about RAID-5 by this point in the thread? >> >> What? Sorry, I wasn't paying attention... >> >> You mean someone's actually still using RAID-5? >> >> ;-) > > What exactly is wrong with RAID5 and what should we have gone with?
RAID 5 is only suitable for situations where you need maximum storage for minimum cost and the database is mostly / all read all the time. Like large reporting databases. It's slow on writes, and it has a low tolerance for dead drives (2 and it's all gone) HOWEVER. RAID-10, which is theoretically MUCH better, is only better if it's implemented right, and lot of cheap RAID controllers don't do any better running RAID-10. Many of these can be put into JBOD mode where you do RAID-10 in the kernel, or you can do RAID-1 on the card (x sets) And RAID-0 in the kernel. RAID-10 is almost always the right choice when you're buying good controllers and fast drives and you want maximum performance. If you REALLY need a lot of storage, and you have to use something like RAID 5 at least look at RAID 6. -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
