From: Albert Cervera Areny <albert@sedifa.com>
To: pgsql-performance@postgresql.org
Cc: Luke Lonergan <llonergan@greenplum.com>
Subject: Re: Bad RAID1 read performance
Date: Thu, 31 May 2007 13:00:49 +0200
Message-ID: <200705311300.50306.albert@sedifa.com> (raw)
In-Reply-To: <C2832909.31C9D%llonergan@greenplum.com>
References: <C2832909.31C9D%llonergan@greenplum.com>
As you suggested with two threads I get 42.39 Mb/s in one and 40.70 Mb/s in
the other one, so that's more than 80Mb/s. That's what I expected with a
single thread, so thanks for the information. It seems I will have to buy
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. Mirror sets can nearly double the read
> 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.
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To: pgsql-performance@postgresql.org
Cc: albert@sedifa.com, llonergan@greenplum.com
Subject: Re: Bad RAID1 read performance
In-Reply-To: <200705311300.50306.albert@sedifa.com>
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