On 05/11/2010 01:31 PM, Daniel Berteaud wrote: > Hi. > > I've just tested the snapshot function, which seems to work, but for > now, is limited to qcow2 images. > > Are there any plans to add LVM based snapshots ? > > I know LVM would have some limitations, but, with recent distribs (F13, > RHEL6 at least), as snapshots can be merged back into the original LV, I > think we could have at least some snapshots function. > > Basically, the domain could be paused, then, the memory can be dumped in > a separated file (as a virsh save do), then, all LVM based disks (and > qcow2 based) could be snapshoted, then, the domain could be reloaded > from the saved state. (or even just resumed, if the save function don't > destroy it like a virsh save does) > > LVM gives some (a lot of ?) performance improvements over qcow2, and I > think snapshots would be a lot faster (on my tests, it takes 4 or 5 > minutes to snapshot a simple ubuntu guest on qcow2, and even longer to > revert). > > There would still be some limitations, like: > - check if lvconvert support merging before we create the snapshots > - size of snapshots are fixed, should libvirt monitor the % used, and > auto-grow when needed ? > - there would be no support for snapshot of snapshot > > Any thoughts ? 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! -- Chris Lalancette -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list