Re: [Xen-users] domU on aoe troubles (saved by losetup?)

[Tom Brown <tbrown@xxxxxxxxxxxxx>]

On Sat, 1 Sep 2007, Steven wrote:

> Chris Fanning wrote:
> >  Hello everybody,
> >
> >  I'm a bit stuck :(
> >
> >  I am trying to setup diskless xen servers.
> >  I can boot dom0 via nfs and setup swap on nbd. that's ok.
> >
> >  Now I'm trying to use aoe for the domU's.
> >
> >  When I try to use the etherd devices the domU boot hangs when mounting
> >  root filesystem
> >  /etc/xen/domU.config
> >  disk = ['phy:etherd/e0.0p1,hda1,w']
> >
> >  But if I do
> >  losetup /dev/loop0 /dev/etherd/e0.0p1
> >
> >  and modify /etc/xen/domU.config accordingly
> >  disk = ['phy:loop0,hda1,w']
> >
> >  then domU boots! :)
> >
> >  I was wondering why I can't use etherd/e0.0p1 directly.
> >  What would be a good way to deal with this? with loop devices?
> Did you find out why and how to fix it?
> I use aoe and domU hangs too when I select etherd/e0.0p1 directly.
AFAIK you need to use an initrd file to boot directly off of AOE ... 
partly because you need to slow down the boot process a bit to let 
auto-discovery take place.
You might also get away with specifying IP config parameters for your 
interface, as that _might_ cause it to be up instead of the default down 
(which will obviously kill aoe).
My changes to the initrd scripts are basically

   /bin/busybox ifconfig eth0 up
   echo hello world > /dev/etherd/discover
   sleep 5

I also build some devices as I've had mixed experiences with udev
doing what I want, but clearly "ifconfig eth0 up" is important...

Anyhow, I/we use the above process on production domUs. The
advantage to doing it this way is that you can easily migrate the
domains... and if you are using vblade for an AOE server, and
DRBD to mirror the underlying storage, you can actually move the
vblade process around... the domU kernel very quickly picks up
the new MAC address :) ... now I just need to get better at
moving drbd processes around, as I need to simplify some things
here.

-Tom


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users