[libvirt] RFCv2: virDomainSnapshotCreateXML enhancements

[Stefan Hajnoczi]

On Wed, Aug 10, 2011 at 11:08 PM, Eric Blake <eblake at redhat.com> wrote:
> disk snapshot: the state of a virtual disk used at a given time; once a
> snapshot exists, then it is possible to track a delta of changes that have
> happened since that time.

Did you go into details of the delta API anywhere?  I don't see it.

My general feedback is that you are trying to map all supported
semantics which becomes very complex.  However, I'm a little concerned
that this API will require users to become experts in
snapshots/checkpoints.  You've mentioned quite a few exceptions where
a force flag is needed or other action is required.  Does it make
sense to cut this down to a common abstraction that mortals can use?
:)

Regarding LVM, btrfs, etc support: eventually it would be nice to
support these storage systems as well as storage appliances (various
SAN and NAS boxes that have their own APIs).  If you lay down an
interface that must be implemented in order to enable snapshots on a
given storage system, then others can contribute the actual drivers
for storage systems they care about.

Stefan