Hi Stephen,

On Thu, Nov 17, 2005 at 03:07:38PM +0000, Stephen Borrill wrote:
> With an IBM x206 and 3.0_BETA as of about a week ago, I see a very big
> difference in apparent disk write performance between dom0 and booting=20
> from a GENERIC kernel.
>=20
> Using "dd if=3D/dev/zero of=3D/dev/rwd1d bs=3D1m", I get about 11MB/s und=
er Xen,=20
> but 59MB/s with GENERIC. Is such a difference to be expected?
=20
this is far more than I'd expect from my experience:

NetBSD xen-host-2 3.0_BETA NetBSD 3.0_BETA (XEN0) #0: Sat Aug 13 13:50:25 U=
TC 2005  builds@works.netbsd.org:/home/builds/ab/netbsd-3/i386/200508120000=
Z-obj/home/builds/ab/netbsd-3/src/sys/arch/i386/compile/XEN0 i386


xen-host-2# dd if=3D/dev/zero of=3Dlala bs=3D1024k count=3D1024
1024+0 records in
1024+0 records out
1073741824 bytes transferred in 19.658 secs (54621112 bytes/sec)

on my domUs (which live on a smaller and slower disk and also of course
experience some overhead) I get approx 13MB/s.

I can't guess on a good reason for what You experience, though. :/

Rgds,
Florian

--
florian heigl                    http://deranfangvomen.de/

Grid Computing erfreut sich gerade bei Windows-Nutzern sehr regem Zuspruch,=
 auch
wenn die Rechnerbesitzer meist nichts von ihrem Gl=FCck wissen. --f. weimer