On Sat, Nov 01, 2003 at 12:14:45AM +0100,
Simon Matter wrote:
> > On Fri, Oct 31, 2003 at 04:50:13PM -0500,
> > Andrew Klaassen wrote:
> >> I've been experiencing *very* slow sustained write ( <
> >> .5MB/sec) using 2.4.20-20.9.XFS1.3.1smp on a dual-Xeon box
> >> with a 3ware 7506 card in JBOD mode. Software RAID 5. No
> >> such problems with Ext3 ( > 20MB/sec sustained write) with
> >> the same kernel on the same software RAID 5 device.
> >> Obviously there's something very wrong here.
> >> Known issue? Any idea what might be causing this?
> > By the way: Using hardware RAID 5 on exactly the same setup,
> > the XFS and EXT3 numbers are virtually identical (~5MB/sec
> > sustained write). Only software RAID 5 seems to cause this
> > great divergence.
> Did you try your setup with an external log? IIRC the problem
> with bad write performance on software RAID 5 should have been
> adressed and mostly fixed with the XFS1.3.x release. I
> recommend to try with external log anyway. I never had good
> results on my software RAID 5 configurations until I used
> external log. However, I never did my tests again in the
> XFS1.3.x days.
No, I haven't. I'll give that a try.