Re: [libvirt] snapshots and LVM
On 05/11/2010 02:01 PM, Daniel Berteaud wrote:
Le mardi 11 mai 2010 à 13:39 -0400, Chris Lalancette a écrit :
>
> It's certainly something that would be nice to see. I even have FIXME
> comments in the code about supporting LVM snapshots; I just haven't had
> time to take any look at it. If you have time/interest, I'd be happy to
> review patches doing it!
I saw your comments in the snapshot code, I was just waiting for
snapshot merging to be available to start talking about LVM snapshot
support (because, without merging, snapshots are not very useful ;))
Well, it does support merging, to a degree, though it's an implicit
feature in the way the other snapshot mechanisms work. That is, if you
do something like:
Base Image -> snap1 -> snap2 -> snap3
And now delete snap2, the changes from snap2 are automatically merged
into snap3 to keep snap3 a viable snapshot.
I think we'll have to explicitly do this for LVM (though I'm not sure;
my experience with LVM snapshotting is 0).
Besides this implicit merging action, do you want/need the ability to
manually merge snapshots? What's your use-case, so I can understand
it better?
--
Chris Lalancette