On Wed, Feb 12, 2014 at 09:22:29AM -0800, Ian Main wrote: > On Wed, Jan 29, 2014 at 01:07:27PM +0800, Fam Zheng wrote: > > This series adds for point-in-time snapshot NBD exporting based on > > blockdev-backup (variant of drive-backup with existing device as target). > > > > We get a thin point-in-time snapshot by COW mechanism of drive-backup, and > > export it through built in NBD server. The steps are as below: > > > > 1. (SHELL) qemu-img create -f qcow2 BACKUP.qcow2 <source size here> > > > > (Alternatively we can use -o backing_file=RUNNING-VM.img to omit > > explicitly > > providing the size by ourselves, but it's risky because > > RUNNING-VM.qcow2 is > > used r/w by guest. Whether or not setting backing file in the image file > > doesn't matter, as we are going to override the backing hd in the next > > step) > > > > 2. (QMP) blockdev-add backing=source-drive file.driver=file > > file.filename=BACKUP.qcow2 id=target0 if=none driver=qcow2 > > > > (where source-drive is the running BlockDriverState name for > > RUNNING-VM.img. This patch implements "backing=" option to override > > backing_hd for added drive) > > > > 3. (QMP) blockdev-backup device=source-drive sync=none target=target0 > > > > (this is the QMP command introduced by this series, which use a named > > device as target of drive-backup) > > > > 4. (QMP) nbd-server-add device=target0 > > > > When image fleecing done: > > > > 1. (QMP) block-job-cancel device=source-drive > > > > 2. (HMP) drive_del target0 > > > > 3. (SHELL) rm BACKUP.qcow2 > > > > v12 -> v13: Address comments from Stefan. > > > > [05/15] block: Add bdrv_set_backing_hd() > > Remove duplicated assignments. > > > > [10/15] qmp: Add command 'blockdev-backup' > > Add check for source == target. > > > > [13/15] block: Add blockdev-backup to transaction > > New. > > > > [14/15] qemu-iotests: Test blockdev-backup in 055 > > New. > > > > [15/15] qemu-iotests: Image fleecing test case 081 > > New. Hope this number has no conflict. I have a 080 on my > > iothrottling test branch. > > > > v11 -> v12: Rebase to qemu.git. > > Call bdrv_refresh_limits() in bdrv_set_backing_hd(). > > I've been using this patch and testing it for the last few weeks and it > all seems to be working very well. Kevin is waiting on more reviewers for > this rev before it can go in. Can someone else look through this please? > > Tested-by: Ian Main <im...@redhat.com>
Adding Pino Toscano to this thread, since he is working on libguestfs. Pino, I believe the latest patch series is this: https://lists.gnu.org/archive/html/qemu-devel/2014-01/threads.html#03904 Rich. > > Fam Zheng (14): > > block: Add BlockOpType enum > > block: Introduce op_blockers to BlockDriverState > > block: Replace in_use with operation blocker > > block: Move op_blocker check from block_job_create to its caller > > block: Add bdrv_set_backing_hd() > > block: Add backing_blocker in BlockDriverState > > block: Parse "backing" option to reference existing BDS > > block: Support dropping active in bdrv_drop_intermediate > > stream: Use bdrv_drop_intermediate and drop close_unused_images > > qmp: Add command 'blockdev-backup' > > block: Allow backup on referenced named BlockDriverState > > block: Add blockdev-backup to transaction > > qemu-iotests: Test blockdev-backup in 055 > > qemu-iotests: Image fleecing test case 081 > > > > block-migration.c | 7 +- > > block.c | 306 > > ++++++++++++++++++++++++++-------------- > > block/backup.c | 26 ++++ > > block/commit.c | 1 + > > block/stream.c | 30 +--- > > blockdev.c | 118 ++++++++++++++-- > > blockjob.c | 14 +- > > hw/block/dataplane/virtio-blk.c | 19 ++- > > include/block/block.h | 29 +++- > > include/block/block_int.h | 9 +- > > include/block/blockjob.h | 3 + > > qapi-schema.json | 50 +++++++ > > qmp-commands.hx | 44 ++++++ > > tests/qemu-iotests/055 | 275 ++++++++++++++++++++++++++++++------ > > tests/qemu-iotests/055.out | 4 +- > > tests/qemu-iotests/081 | 99 +++++++++++++ > > tests/qemu-iotests/081.out | 5 + > > tests/qemu-iotests/group | 1 + > > 18 files changed, 836 insertions(+), 204 deletions(-) > > create mode 100755 tests/qemu-iotests/081 > > create mode 100644 tests/qemu-iotests/081.out > > > > -- > > 1.8.5.3 > > -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Fedora Windows cross-compiler. Compile Windows programs, test, and build Windows installers. Over 100 libraries supported. http://fedoraproject.org/wiki/MinGW