Message-ID: <44901DF7.7010200@aeccom.com>
Date: Wed, 14 Jun 2006 16:32:23 +0200
From: Sven Geisler <sgeisler@aeccom.com>
Organization: AEC/communications GmbH
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To: Richard Broersma Jr <rabroersma@yahoo.com>
CC: Pgsql-Performance <pgsql-performance@postgresql.org>
Subject: Re: how to partition disks
References: <20060614142344.13558.qmail@web31804.mail.mud.yahoo.com>
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Hi Richard,

Richard Broersma Jr schrieb:
>> This depends on your application. Do you have a lot of disc reads?
>> Anyhow, I would put the xlog always to a RAID 10 volume because most of 
>> the I/O for update and inserts is going to the xlog.
>>
>> 4 discs xlog
>> 6 discs tables
>> 4 discs tables2
> 
> I have a question in regards to I/O bandwidths of various raid configuration.  Primary, does the
> above suggested raid partitions imply that multiple (smaller) disk arrays have a potential for
> more I/O bandwidth than a larger raid 10 array?

Yes.
Because the disc arms didn't need to reposition that much as there would 
o with one large volume.

For example, You run two queries with two clients and each queries needs 
to read some indices from disk. In this case it more efficient to read 
from different volumes than to read from one large volume where the disc 
arms has to jump.

Sven.