From: David Chinner <dgc@sgi.com>
To: Mario Kadastik <mario.kadastik@cern.ch>
Cc: xfs@oss.sgi.com
Subject: Re: raw vs XFS sequential write and system load
Date: Fri, 19 Oct 2007 08:23:57 +1000 [thread overview]
Message-ID: <20071018222357.GN995458@sgi.com> (raw)
In-Reply-To: <B4D42128-E5B2-48B1-AEF1-586FD90AF605@cern.ch>
On Thu, Oct 18, 2007 at 12:50:44PM +0200, Mario Kadastik wrote:
> Hello,
>
> I have a slight problem. Namely we have 4 systems with each having 2x
> 3ware 9550SX cards in them each with hardware RAID5. Everything is
> running the latest FW etc. The systems have at least 3GB of memory
> and at least 2 CPU-s (one has 4GB and 4 cpu-s).
Before going any further, what kernel are you using and what's
the output of xfs_info </mntpt> of the filesytsem you are testing?
FWIW, high iowait = high load average. High iowait is generally an
indicator of an overloaded disk subsystem. You tests to the raw
device only used a single stream, so it's unlikely to show any of
the issues you're complaining about when running tens of parallel
streams....
Cheers,
Dave.
--
Dave Chinner
Principal Engineer
SGI Australian Software Group
next prev parent reply other threads:[~2007-10-18 22:24 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-18 10:50 raw vs XFS sequential write and system load Mario Kadastik
2007-10-18 22:23 ` David Chinner [this message]
2007-10-19 6:12 ` Mario Kadastik
2007-10-19 7:59 ` David Chinner
2007-10-19 10:11 ` Mario Kadastik
2007-10-27 11:30 ` Mario Kadastik
2007-10-27 13:07 ` Justin Piszcz
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