[libvirt] Domain XML isn't dumping full backing chain

[Eric Blake]

On 03/18/2015 07:03 AM, Deepak Shetty wrote:

[please don't top-post on technical lists]

> Hmm interesting, so without adding backing_fmt, if i enable the below in
> /etc/libvirt/qemu.conf, will it work ?
> 
> # If allow_disk_format_probing is enabled, libvirt will probe disk
> # images to attempt to identify their format, when not otherwise
> # specified in the XML. This is disabled by default.
> #
> # WARNING: Enabling probing is a security hole in almost all
> # deployments. It is strongly recommended that users update their
> # guest XML <disk> elements to include  <driver type='XXXX'/>
> # elements instead of enabling this option.
> #
> #allow_disk_format_probing = 1

It _might_ work in that libvirt will then probe the backing chain as
qcow2, rather than treating it as raw; on the other hand, the upcoming
qemu 2.3 is trying to deprecate probing altogether because of the
security problems it represented, and so you may reach a point where
even if you tell libvirt it is okay to probe, that qemu will refuse to
open your image if you didn't specify backing format.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 604 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20150318/af46bfbf/attachment-0001.sig>