[libvirt] Createion of external snapshot qcow2

[Eric Blake]

On 03/25/2012 11:18 PM, Pankaj Rawat wrote:
> Hi all,
> 
>  
> 

[your mailer uses lots of spurious whitespace]

> I have a query regarding the external snapshot in qcow2 also known as
> backing file.
> 
> In qemu I created a external snapshot and then create its xml in order
> to boot it from VIRSH. But that is complex process.
> 
> I want to know whether there is any command in LIBVIRT which can create
> external snapshot(Backing file) and also we can boot from it?

The virDomainSnapshotCreateXML is designed to help you create external
snapshots, but I have not yet had the time to write the patches to wire
up the qemu support for creation of external snapshots of offline
domains (right now, you have to use 'virsh snapshot-create --disk-only'
on a running domain).  Patches are welcome to help libvirt use qemu-img
under the hood for offline external snapshot creation.

Meanwhile, the <volume> XML for use in virStorageVolCreateXML supports
the <backingStore> sub-element which maps to qemu-img, so it _is_
possible to use libvirt to create external snapshots, but you have to
then hand-edit the <domain> XML to change the <disk> elements to point
to those just-created qcow2 files.

> The contents of this e-mail and any attachment(s) are confidential and
> intended

This legalese is unenforceable on publicly-archived mailing lists.  If
your company insists on tacking on such disclaimers, then good
netiquette would be to send from an alternate email address not owned by
your employer.

-- 
Eric Blake   eblake at 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: 620 bytes
Desc: OpenPGP digital signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20120326/f0ca85f8/attachment-0001.sig>