From: Fernando Hevia <fhevia@ip-tel.com.ar>
To: 'Mark Mielke' <mark@mark.mielke.cc>
Cc: 'pgsql-performance' <pgsql-performance@postgresql.org>
Subject: Re: With 4 disks should I go for RAID 5 or RAID 10
Date: Wed, 26 Dec 2007 16:32:21 -0300
Message-ID: <0f8201c847f6$08e15090$8f01010a@iptel.com.ar> (raw)
In-Reply-To: <47728000.4000709@mark.mielke.cc>
Mark Mielke Wrote:
>In my experience, software RAID 5 is horrible. Write performance can
>decrease below the speed of one disk on its own, and read performance will
>not be significantly more than RAID 1+0 as the number of stripes has only
>increased from 2 to 3, and if reading while writing, you will not get 3X as
>RAID 5 write requires at least two disks to be involved. I believe hardware
>RAID 5 is also horrible, but since the hardware hides it from the
>application, a hardware RAID 5 user might not care.
>Software RAID 1+0 works fine on Linux with 4 disks. This is the setup I use
>for my personal server.
I will use software RAID so RAID 1+0 seems to be the obvious choice.
Thanks for the advice!
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To: pgsql-performance@postgresql.org
Cc: fhevia@ip-tel.com.ar, mark@mark.mielke.cc
Subject: Re: With 4 disks should I go for RAID 5 or RAID 10
In-Reply-To: <0f8201c847f6$08e15090$8f01010a@iptel.com.ar>
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