Date: Thu, 31 Mar 2005 17:16:24 -0500
From: Robin Humble <rjh@cita.utoronto.ca>
To: linux-xfs@oss.sgi.com
Subject: Re: RHEL 4 --  how build kernel with xfs?
Message-ID: <20050331221624.GA17344@lemming.cita.utoronto.ca>
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On Thu, Mar 31, 2005 at 01:00:38PM -0800, David Kewley wrote:
>I wonder what they'd say to raw performance numbers.  Maybe something like 

The most disturbing thing about bonnie++ numbers isn't XFS related -
the 'rewrite' speed in 2.6 is dreadful - it's about 6x less than a 2.4
kernel!!!
I think it's a NFS client problem as a 2.4 client talking to a 2.6
server sees ok numbers again. it seems to be filesystem independent.

>"Those differences don't matter in real life." or "Sequential I/O isn't 
>representative of real use." :)  Whatever the case, the more of their 

you'd think RHEL AS4 as an NFS server would be a very common
configuration and that RedHat would want it to go faster... :-/

XFS does well at the large single files workload eg. film industry or
computational cluster. When testing I didn't pay much attention to
benchmarks of small files etc., but maybe it's not so good at that.

Still, choice is a good thing, and for a proportion of RedHat customers
it'd be a significant win.

>customers make the case to them for supporting xfs, and the more that provide 
>good hard reasons why, the more likely they are to consider investing in 
>in-house xfs expertise.

indeed.

>to me.  I took a gander at your website, and it sounds like we're in similar 
>situations.  I'm a sysadmin for a computational geophysics beowulf.  The 

computational astrophysics here.

>fileserver I'm asking about is a 9.6TB raw (24x400) 3-ware 9500 based box. :)

yup, pretty much the same here except we haven't got the box fully loaded
with disks yet. seems like a nice toy :)

cheers,
robin