From: Linda Walsh <xfs@tlinx.org>
To: rkj@softhome.net
Cc: xfs-oss <xfs@oss.sgi.com>
Subject: Re: Looking for Linux XFS file system performance tuning tips for LSI 9271-8i + 8 SSD's RAID0
Date: Mon, 04 Feb 2013 01:11:09 -0800 [thread overview]
Message-ID: <510F7B2D.908@tlinx.org> (raw)
In-Reply-To: <courier.510ECA60.00003A99@softhome.net>
rkj@softhome.net wrote:
>
> I am working with hardware RAID0 using LSI 9271-8i + 8 SSD's...
>... With Direct IO, the sequential writes are around
> 3.5 GB/s but I noticed a drop-off in sequential reads for smaller record
> sizes.
----
1) Are you using the realtime partitions?
2) are you using an empty file space with max log size
3) what are you using to do write's with, "dd"?
4) have you tried pre-allocating the space, running xfs_fsr on the
file, to get it to 1 extent in size,
then run dd with the conv=nocreat,notrunc option?
Those are some things to try for maximums.
I notice ~30% hit if I go through the linux buffer system as well.
Have you tried different write sizes?
i.e. 32M, 64M, 128 256... i.e. I notice optimal sizes after
which things fall off...
do you run 'time' on "dd" as well and see how much cpu it is using?
If you use bash, I find setting TIMEFORMAT to:
"%2Rsec %2Uusr %2Ssys (%P%% cpu)"
to be a useful format (1 line, and shows cpu % usage)...
just some random thoughts...
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next prev parent reply other threads:[~2013-02-04 9:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-03 20:36 Looking for Linux XFS file system performance tuning tips for LSI 9271-8i + 8 SSD's RAID0 rkj
2013-02-04 9:11 ` Linda Walsh [this message]
2013-02-04 12:52 ` Looking for Linux XFS file system performance tuning tips for LSI9271-8i " Dave Chinner
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