ok, I see, thank you very much for your kindly reply, the answer is very clear and useful for me. Thanks a lot! 2012/5/29 Eric Blake <eblake@redhat.com>
On 05/29/2012 03:40 AM, Rujie Xu wrote:
Hello everyone, I am trying to find a way to store an internal disk snapshot and supposed to restore later.
Here is the problems I met: 1) when I use SnapshotCreateXML() to create a disk_only snapshot while the domain is inactive, there is an error happened: disk snapshot of inactive domains not implemented yet. I am wondering is there and way I can save the disk_only snapshot when the domain is inactive right now?
That code still has to be written. It's on my todo list.
https://bugzilla.redhat.com/show_bug.cgi?id=817226
That said, if you _don't_ use the disk_only flag and the domain is offline, then the end result right now is that you get internal snapshots for free (since a system checkpoint of an offline domain _is_ the disk snapshot, and since system checkpoint currently uses internal snapshots only).
2) also use snapshotCreateXML() to create a disk_only snapshot while the domain is active, and use the xml to set the <disk name="hda" snapshot="internal"> there is also an error happened: unsupported configuration: active qemu domains require external disk snapshot; disk hda requested internal
Correct. Qemu does not support the creation of internal disk snapshots except by the 'savevm' command which takes a system checkpoint snapshot (that is, unless qemu gives us a way to do disk-only internal snapshots of a running VM, you are stuck on this front).
3) when I use snapshotCreateXML() to create a disk_only snapshot
using
external file, it could be done, but when I try to use revertToSnapshot() to revert this snapshot there is another error happened: revert to external snapshot not supported yet.
Correct, that's another API that I haven't yet coded; and you're the second person to ask about it this week: https://www.redhat.com/archives/libvirt-users/2012-May/msg00122.html
Is there anyone can help me about this, or we just can't use libvirt to managed the disk snapshot right now?
Help in contributing code would be very welcome.
-- Eric Blake eblake@redhat.com +1-919-301-3266 Libvirt virtualization library http://libvirt.org
-- Regards, Roger Xu