Re: Article about PostgreSQL and RAID in Brazil - Mailing list pgsql-performance

From Josh Berkus
Subject Re: Article about PostgreSQL and RAID in Brazil
Date
Msg-id 200409161407.37669.josh@agliodbs.com
Whole thread Raw
In response to Re: Article about PostgreSQL and RAID in Brazil  ("Jim C. Nasby" <decibel@decibel.org>)
Responses Re: Article about PostgreSQL and RAID in Brazil
List pgsql-performance
Jim,

> What about benefits from putting WAL and pg_temp on seperate drives?
> Specifically, we have a box with 8 drives, 2 in a mirror with the OS and
> WAL and pg_temp; the rest in a raid10 with the database on it. Do you
> think it would have been better to make one big raid10? What if it was
> raid5? And what if it was only 6 drives total?

OSDL's finding was that even with a large RAID array, it still benefits you to
have WAL on a seperate disk resource ... substantially, like 10% total
performance.    However, your setup doesn't get the full possible benefit,
since WAL is sharing the array with other resources.

--
--Josh

Josh Berkus
Aglio Database Solutions
San Francisco

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