1.1

On Fri, Feb 15, 2008 at 7:38 AM, Reto Gantenbein
<reto.gantenbein@...> wrote:
> Hello everybody
>
>  After 3 days messing around I'm at my wits' end. I have two Sun X4200M2
>  servers which I would like to setup as Xen dom0s with a drbd-mirrored
>  file system for paravirtualized domU images.
>
>  I setup an LVM2 on top of DRBD to create the domU volumes and to be able
>  to backup the domUs with LVM snapshot.
>
>  I was able to configure this setup and make it run, but when accessing
>  the block-frontend device in domU this is terrible slow. E.g. copying a
>  5G file via scp and gigabit Ethernet onto the domU leads to a lot of
>  stalls during transfer. The peak transfer rate is about 5MB/s every 1-2
>  minutes but generally it's about a few hundred KB/s. When copying the
>  same file onto the DRBD volume mounted directly in dom0 it works with
>  the expected 30-40MB/s. Another test was to sync the portage tree but
>  also this takes maybe about 20 minutes or spontaneously raises some
>  timeout errors. Sometimes after a while the disk fully detaches from the
>  domU, so every call of a binary in domU leads to a "Input/output error".
>  I guess the domU kernel adds this troubles, but why? There are no
>  statements in any log files. E.g. /var/log/xen/xend-debug.log doesn't
>  notify the detached block device.
>
>  I use Gentoo Linux and tried so far with xen-3.1.2 and xen-3.2.0,
>  xen-sources-2.6.18-r8, xen-sources-2.6.20-r6 and xen-sources-2.6.22,
>  drbd-8.0.7, drbd-8.0.8 and drbd-8.0.11.
>
>  The longer the more I expect a general problem with Xen and this setup,
>  a kernel problem or a misconfiguration. Attached are the most important
>  configurations for this setup.
>
>  Are there any hints or other experiences for such a setup? All ideas are
>  welcome.
>
>  Thanks for reading and giving any hints...
>  Cheers Reto Gantenbein

I couldn't quite tell from the above but do you see the bad
performance inside domU only when using scp/rsync or is it just as
slow when you copy files locally?

-- 
Michael Marineau
Oregon State University
mike@...
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