From: Albert Cervera Areny <albert@sedifa.com>
Organization: Sedifa, S.L.
To: pgsql-performance@postgresql.org
Subject: Re: Bad RAID1 read performance
Date: Thu, 31 May 2007 13:00:49 +0200
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Cc: "Luke Lonergan" <llonergan@greenplum.com>
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As you suggested with two threads I get 42.39 Mb/s in one and 40.70 Mb/s in=
=20
the other one, so that's more than 80Mb/s. That's what I expected with a=20
single thread, so thanks for the information. It seems I will have to buy=20
better hard drives if I want increased performance...

A Dimecres 30 Maig 2007 22:13, Luke Lonergan va escriure:
> Not for one thread/process of I/O. =A0Mirror sets can nearly double the r=
ead
> performance on most RAID adapters or SW RAID when using two or more
> thread/processes, but a single thread will get one drive worth of
> performance.
>
> You should try running two simultaneous processes during reading and see
> what you get.

=20