[ovirt-devel] [Hackathon] oVirt session non-notes

[Dan Kenigsberg]

I've used the occasion of http://wiki.xen.org/wiki/Hackathon/May2014 to
learn how Xen is managed, and to start scoping how it can be done within
oVirt.

I've laid out my impressions on http://www.ovirt.org/Xen; some of it
may false. For example, up until few minutes ago, it stated that Xen is
missing spice support. Feel free to fix it, it's a wiki.

The bottom line is that, with a bit of help, and with limited feature
set, oVirt can manage Xen-based hypervisors. I've posted a couple of
Vdsm tweaks to support that
http://gerrit.ovirt.org/#/q/status:open+project:vdsm+branch:master+topic:xen,n,z

The nicest patch there is a brute script that munches an oVirt-generated
libvirt domxml and strips it from anything that it finds offensive to
libvirt's xl driver.
http://gerrit.ovirt.org/#/c/28353/1/vdsm_hooks/xen/before_vm_start.py

The most painful of the things dropped is qcow2 images - I did not find
a way to specify them for Xen domains (admittedly, I did not search too
deep).

Another hurdle was my failure to boot the guest from its cdrom. To have
something running in the guest, I copied
http://download.fedoraproject.org/pub/fedora/linux/updates/20/Images/x86_64/Fedora-x86_64-20-20140407-sda.raw.xz
onto the VM disk volume.

Plenty of other caveats are listed in
http://www.ovirt.org/Xen#What.27s_not_Done. But hey, it's working!(ish)

I'd like to thank the all nice and helpful people at the Xen hackathon
(too many to mention by name!), who invited me there and helped me debug
numerous failures and misconfigurations.

Regards,
Dan.