[xenpreview-dev] Extremely poor performance on SUSE 10 dom0

[Lynn Bendixsen]

G'day Paul,

I do not know why you are seeing perfomance problems in Xen on SUSE
10.0.  I do know, though, that all of the fixes/enhancements that are
being done for Xen 3.0 are not being put into SUSE 10.0.  All of our
(Novell/SUSE's) current efforts for Xen are going into SUSE 10.1 and
SLES 10.  Over 1200 more changesets have gone into the newer stuff so my
recommendation is that if you like Xen and have the ability to do so,
move to a newer version of SUSE Linux.  I'm pretty sure you'll be glad
you did, but if you are still having the same issues there that you are
having on 10.0 be sure and give us some more feedback.

Thanks for checking out Xen,
Lynn

>>> Paul Gear <pgear at redlands.qld.edu.au> 04/12/06 6:31 pm >>> 
Hi folks,

I don't know whether this is the intended place to discuss these
issues,
but i'm having some extremely irritating performance problems trying
to
get a Xen system up and running.  I'm following the SUSE Linux Xen
live
migration demo HOWTO from
http://developer.novell.com/wiki/index.php/Image:XEN_migration_demo_1.1.pdf

I'm using SUSE 10.0 x64-64 with xen-3.0_8259-0.1 (obtained from YOU,
but
also seems to be the latest available on forge.novell.com), and
whenever
i boot the Xen kernel, the system slows to a fraction of its native
performance.

My hardware is:
- Dell PE SC1425, 2 x Xeon 2.8, 2 x 2 GB DDR2 RAM, 2 x 250 GB SATA
- Dell PE 850, Pentium D 830 (3.0 GHz), 4 x 1 GB DDR2 RAM, 2 x 250 GB
SATA

My intent is to use these two machines as dom0 platforms for live
migration of 5 domUs, and host the domU filesystems on iSCSI over
1000baseT, served from a dedicated NetWare 6.5 SP5 iSCSI target.

I haven't even made it to booting a domU yet, as the performance of
the
system is so poor.  My first "yast2 dirinstall" is running now, and i
hope to get the domU up & running sometime today.

The Xeon system supports hyperthreading, and i've tried with and
without
this, but it makes little difference - if anything without HT is
slightly slower.  When i'm doing ordinary work (e.g. setting up
filesystems, running YAST), the problem manifests as a CPU load
usually
somewhere over 2.5, but utilisation somewhere below 25%.

Could anyone suggest why i'm seeing this behaviour?

Regards,
Paul Gear, Manager IT Operations, Redlands College
38 Anson Road, Wellington Point 4160, Australia
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Lynn Bendixsen
Software Engineer
lbendixs at novell.com
Novell, Inc.