2010/12/18 Gael Le Mignot <g...@pilotsystems.net>: > Hello Scott! > > Fri, 17 Dec 2010 19:06:15 -0700, you wrote: > > > On Fri, Dec 17, 2010 at 10:32 AM, Craig James > > <craig_ja...@emolecules.com> wrote: > >> RAID5 is a Really Bad Idea for any database. It is S...L...O...W. It > does > >> NOT give better redundancy and security; RAID 10 with a battery-backed > RAID > >> controller card is massively better for performance and just as good for > >> redundancy and security. > > > The real performance problem with RAID 5 won't show up until a drive > > dies and it starts rebuilding > > I don't agree with that. RAID5 is very slow for random writes, since > it needs to :
Trust me I'm well aware of how bad RAID 5 is for write performance. But as bad as that is, when the array is degraded it's 100 times worse. For a lot of workloads, the meh-grade performance of a working RAID-5 is ok. "Not a lot of write" data warehousing often runs just fine on RAID-5. Until the array degrades. Then it's much much slower than even a single drive would be. -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
