[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH V5 0/8] add internal snapshot support at block d
From: |
Kevin Wolf |
Subject: |
Re: [Qemu-devel] [PATCH V5 0/8] add internal snapshot support at block device level |
Date: |
Thu, 18 Jul 2013 14:34:52 +0200 |
User-agent: |
Mutt/1.5.21 (2010-09-15) |
Am 11.07.2013 um 07:46 hat Wenchao Xia geschrieben:
> This series brings internal snapshot support at block devices level, now we
> have two three methods to do block snapshot lively: 1) backing chain,
> 2) internal one and 3) drive-back up approach.
>
> Comparation:
> Advantages: Disadvantages:
> 1) delta data, taken fast, export, size performance, delete slow.
> 2) taken fast, delete fast, performance, size delta data, format
> 3) performance, export, format taken slow, delta data, size
>
> I think in most case, saving vmstate in an standalone file is better than
> saving it inside qcow2, So suggest treat internal snapshot as block level
> methods and not encourage user to savevm in qcow2 any more.
>
> Implemention details:
> To avoid trouble, this serial have hide ID in create interfaces, this make
> sure no chaos of ID and name will be introduced by these interfaces.
> There is one patch may be common to Pavel's savvm transaction, patch 1/11,
> others are not quite related. Patch 1/11 will not set errp when no snapshot
> find, since patch 3/11 need to distinguish real error case.
>
> Next steps to better full VM snapshot:
> Improve internal snapshot's export capability.
> Better vmstate saving.
>
> Thanks Kevin to give advisement about how add it in qmp_transaction, oldest
> version comes drom Dietmar Maurer.
>
> v3:
> General:
> Rebased after Stenfan's driver-backup patch V6.
>
> Address Eric's comments:
> 4/9: grammar fix and better doc.
> 5/9: parameter name is mandatory now. grammar fix.
> 6/9: redesiged interface: take both id and name as optional parameter,
> return
> the deleted snapshot's info.
>
> Address Stefan's comments:
> 4/9: add '' around %s in message. drop code comments about vm_clock.
> 9/9: better doc, refined the code and add more test case.
>
> v4:
> Address Stefan's comments:
> 4/9: use error_setg_errno() to show error reason for bdrv_snapshot_create(),
> spell fix and better doc.
> 5/9: better doc.
> 6/9: remove spurious ';' in code, spell fix and better doc.
>
> v5:
> Address Kevin's comments:
> 3/8, 4/8, 8/8: remove the limit of numeric snapshot name.
> General change:
> 4/8: use existing type as parameter in qapi schema.
>
> Wenchao Xia (8):
> 1 snapshot: new function bdrv_snapshot_find_by_id_and_name()
> 2 snapshot: distinguish id and name in snapshot delete
> 3 qmp: add internal snapshot support in qmp_transaction
> 4 qmp: add interface blockdev-snapshot-internal-sync
> 5 qmp: add interface blockdev-snapshot-delete-internal-sync
> 6 hmp: add interface hmp_snapshot_blkdev_internal
> 7 hmp: add interface hmp_snapshot_delete_blkdev_internal
> 8 qemu-iotests: add 056 internal snapshot for block device test case
Okay, reviewed the whole series. I had some comments on two or three
patches.
One thing that I want to add is that in order to provide transactional
behaviour (i.e. snapshotting multiple device in one transaction should
result in a consistent snapshot), I think we may in fact need to stop
the VM while taking the snapshots.
Kevin
- Re: [Qemu-devel] [PATCH V5 2/8] snapshot: distinguish id and name in snapshot delete, (continued)
- [Qemu-devel] [PATCH V5 3/8] qmp: add internal snapshot support in qmp_transaction, Wenchao Xia, 2013/07/11
- [Qemu-devel] [PATCH V5 4/8] qmp: add interface blockdev-snapshot-internal-sync, Wenchao Xia, 2013/07/11
- [Qemu-devel] [PATCH V5 5/8] qmp: add interface blockdev-snapshot-delete-internal-sync, Wenchao Xia, 2013/07/11
- [Qemu-devel] [PATCH V5 6/8] hmp: add interface hmp_snapshot_blkdev_internal, Wenchao Xia, 2013/07/11
- [Qemu-devel] [PATCH V5 7/8] hmp: add interface hmp_snapshot_delete_blkdev_internal, Wenchao Xia, 2013/07/11
- [Qemu-devel] [PATCH V5 8/8] qemu-iotests: add 056 internal snapshot for block device test case, Wenchao Xia, 2013/07/11
- Re: [Qemu-devel] [PATCH V5 0/8] add internal snapshot support at block device level, Stefan Hajnoczi, 2013/07/18
- Re: [Qemu-devel] [PATCH V5 0/8] add internal snapshot support at block device level,
Kevin Wolf <=