Re: XFS + SMP + Software RAID 5 slow?

[Andrew Klaassen <ak@xxxxxxx>]

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.

Andrew Klaassen