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Re: What's the best hardver for PostgreSQL 8.1?

From: William Yu <wyu(at)talisys(dot)com>
To: pgsql-performance(at)postgresql(dot)org
Subject: Re: What's the best hardver for PostgreSQL 8.1?
Date: 2005-12-25 03:43:52
Message-ID: dol4hh$o0l$1@news.hub.org (view raw or flat)
Thread:
Lists: pgsql-performance
Luke Lonergan wrote:
> Note that host-based SCSI raid cards from LSI, Adaptec, Intel, Dell, HP
> and others have proven to have worse performance than a single disk
> drive in many cases, whether for RAID0 or RAID5.  In most circumstances

This is my own experience. Running a LSI MegaRAID in pure passthrough 
mode + Linux software RAID10 is a ton faster than configuring the RAID 
via the LSI card. One of the things I've noticed is that the card does 
not seem to be able to parallel read on mirrors. While looking at iostat 
under Linux, I can see software RAID1 reading all drives and the MD 
number adding up to the sum of all drives.

The ARECA SATA controller I just got though doesn't seem to exhibit 
these problems. Performance is a few % points above Linux software RAID 
at lower CPU usage. In fact, I'm getting better single-threaded 
bandwidth on a 4x7200RPM SATA config versus a 6x15K SCSI config on the 
LSI. The drives are bigger for the SATA drive (300GB) versus 36GB for 
the SCSI so that means the heads don't have to move any where as much 
and can stay on the fast portion of the disk. Haven't had a chance to 
test multi-user DB between the two setup though.

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Next:From: Joshua D. DrakeDate: 2005-12-25 04:18:55
Subject: Re: What's the best hardver for PostgreSQL 8.1?
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Subject: Re: What's the best hardver for PostgreSQL 8.1?

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