On Tue, 10/28 09:52, Jd wrote: > Hi > We are looking for dirty block tracking feature in qemu/kvm for > implementing more efficient incremental backup. I saw some patches around > it, but from the conversation could not figure out if it is complete or not. > If it is complete, can some one point to the branch / label from which I can > get it.
It is still unfinished work. No code is written yet for persistent dirty block tracking, although there are some out-of-date patches for live incremental backup. > > Could of questions around the feature. > > * Does this work with qcow format only ? Or for any format ? Can I use > it with ceph, gluster, etc,,etc. It should work with any format, and also network based protocols. > > * How does dirty block tracking to file get affected by snapshots ? One > would assume that it would mark all the blocks changed since tracking begun, > irrespective of snapshots pull / rebase....etc. This way one might copy more > blocks than necessary, but is accurate. And this allows the user to do > different snapshot operations irrespective of backups which is a big thing > from users perspective. I'm not sure I understand your question but I think block jobs are orthogonal to incremental backup so both of them run independently of each other. Anyway, creating a snapshot doesn't change the image's user data, why do you assume it would mark all the blocks dirty? Fam
