On Sun, Mar 10, 2013 at 10:32 AM, Dietmar Maurer <diet...@proxmox.com> wrote: >> >> What I am looking for is a stripped down patch series with just a >> >> backup block job (no backup archive writer or migration code). That >> >> would be easily merged and saves you front rebasing this series as QEMU >> changes. >> > >> > That is Patch 2/6? >> >> Yes. I sent an RFC series that shows this approach. It is just a prototype >> but it >> demonstrates that the NBD approach works and performs reasonably well for a >> quick Python hack. >> >> The stripped down patch series needs: >> 1. (Optional) query-block virtual_size field if management tool needs to >> query >> drive size 2. Patch 2/6 with review comments addressed 3. 'block-backup' QMP >> command (and optionally HMP command) >> >> That's it! > > Thanks. I also have an implementation here using that approach (using nbd.c). > The problem is the performance you get. 28% delay is not acceptable. > > In fact, I want to have the fastest possible solution (additional delay = 0). > > You want to move the code out of qemu, so that management frameworks > can easily plug their own backup tools. That is perfectly valid, but we > should do > it in a way that does not influence performance. > > So are there any other ideas?
Same discussion in the other thread, so let's move there where we both just posted. Stefan
