I'm tracking the following series for Incremental Backup right now; if it's not on this list, I don't know about it:
[Qemu-devel] [PATCH v4 0/2] block: formalize and test fleecing [Qemu-devel] [PATCH v2 0/3] image fleecing [Qemu-devel] [PATCH] migration: Appease coverity, skip empty block trees [Qemu-devel] [PATCH v2 0/2] test NBD bitmap export [Qemu-devel] [PATCH 0/6] fix persistent bitmaps migration logic [Qemu-devel] [PATCH 0/2] dirty bitmap fixes [Qemu-devel] [PATCH v2] qcow2: add overlap check for bitmap directory [Qemu-devel] [PATCH 0/1] blockdev: implement n-ary bitmap merge [Qemu-devel] [PATCH v2 00/10] qemu-img: add bitmap info output Now, in a little more detail below; # Image fleecing: In order to support pull-model semantics for incremental backup, we need working point in time NBD export of live disk images. This was thought supported/finished for quite some time, but we've had no iotests. There are two series in flight here: - [Qemu-devel] [PATCH v4 0/2] block: formalize and test fleecing - [Qemu-devel] [PATCH v2 0/3] image fleecing The first listed there simply loosens restrictions on blockdev-backup and adds an iotest that this approach works in the simple case. The second series adds a fleecing filter to combat deficiencies in the IO serialization that may allow the fleecing node to sometimes see new, live data instead of the PIT data. See https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg00150.html for details. Our current plan is to merge the first series and to continue looking into the fleecing filter during freeze as a potential bugfix. # NBD: - [Qemu-devel] [PATCH v2 0/2] test NBD bitmap export Eric's series that adds a quick hack to our NBD client and an iotest 223 that demos that the bitmap support in our NBD server is working correctly. Notably, we don't have an iotest that combines this with the image fleecing workflow, so there's discussion there that I've started for how to combine the two, comments appreciated: https://lists.gnu.org/archive/html/qemu-devel/2018-07/msg00476.html # Migration/Persistence: - [Qemu-devel] [PATCH 0/6] fix persistent bitmaps migration logic Needs review, but can go in after freeze as a fix. # Bitmap manipulation: - [Qemu-devel] [PATCH 0/1] blockdev: implement n-ary bitmap merge Possibly important to have if we wish to add merge into transactions, as this will greatly simplify the commands needed to be issued to QEMU. Not yet reviewed, but I might submit a PR for this tomorrow in anticipation of its usefulness over the 1-bitmap version. - [Qemu-devel] [PATCH v2 00/10] qemu-img: add bitmap info output On hold until persistence is settled, due to interactions with attempting to cache the bitmap metadata. "offline" bitmap manipulation will need to occur via QMP on QEMU with no running guest in the meantime. We will still need a patch for `qemu-img check -r` that allows us to delete corrupted bitmaps, however. That can be a bugfix for 3.0. There is a follow-up series that's also on hold because it's blocked on this series, that adds the actual add/delete/clear offline functionality. # Miscellaneous: - [Qemu-devel] [PATCH] migration: Appease coverity, skip empty block trees Needs a respin based on Stefan's feedback. Only important so that it doesn't keep annoying Peter Maydell, does not actually fix a bug. - [Qemu-devel] [PATCH 0/2] dirty bitmap fixes Staged: https://github.com/jnsnow/qemu/commits/bitmaps - [Qemu-devel] [PATCH v2] qcow2: add overlap check for bitmap directory Needs a V3 after review from Max. Not crucial for release, but nice to have. So in order to put together a demo from QEMU's point-of-view that both push and pull model are working, I think we still need: - iotest 222 and 223 merged, with their respective enablement patches. - A new iotest (224?) that combines functionality of both; which makes use of perhaps some new features that allow us to tie bitmap manipulation to the start of the node fleecing. - All of the various bugfixes above reviewed and merged. Please let me know if this roadmap is missing anything. Thanks, --js
