From: Casey Allen Shobe <lists@seattleserver.com>
Organization: SeattleServer.com, Inc.
To: John A Meinel <john@arbash-meinel.com>
Subject: Re: Performance nightmare with dspam (urgent) (resolved)
Date: Mon, 6 Jun 2005 16:04:39 +0000
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Cc: Postgresql Performance <pgsql-performance@postgresql.org>
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On Monday 06 June 2005 15:08, John A Meinel wrote:
> Be very careful in this situation. If any disks in a RAID0 fails, the
> entire raid is lost. You *really* want a RAID10. It takes more drives,
> but then if anything dies you don't lose everything.

We have redundancy at the machine level using DRBD, so this is not a concern.

> I don't know if you can do it, but it would be nice to see this be 1
> RAID1 for OS, 1 RAID10 for pg_xlog, and another RAID10 for data. That is
> the recommended performance layout. It takes quite a few drives (minimum
> of 10). But it means your data is safe, and your performance should be
> very good.

The current servers have 4 drive bays, and we can't even afford to fill them 
all right now...we just invested what amounts to "quite a lot" on our budget 
for these 2 servers, so replacing them is not an option at all right now.

I think the most cost-effective road forward is to add 2 more drives to each 
of the existing servers (which currently have 2 each).

Cheers,
-- 
Casey Allen Shobe | http://casey.shobe.info
cshobe@seattleserver.com | cell 425-443-4653
AIM & Yahoo:  SomeLinuxGuy | ICQ:  1494523
SeattleServer.com, Inc. | http://www.seattleserver.com