Re: [Qemu-devel] [PATCH V6 0/8] add internal snapshot support at block device level

[Wenchao Xia <xiawenc@linux.vnet.ibm.com>]

于 2013-7-30 10:59, Wenchao Xia 写道:
>>     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.
>>
>> v6:
>>     Address Stefan's comments:
>>     2/8: macro STR_PRINT_CHAR was renamed as STR_OR_NULL, and moved into patch 5,
>> since implement function in this patch do not printf snapshot id any more, as
>> Kevin's suggestion.
>>     Address Kevin's comments:
>>     2/8: remove device, id, name info in the error message, use error message in
>> existing caller. A new function bdrv_snapshot_delete_by_id_or_name() is added
>> to make the usage clear while keep logic unchanged.
>>     3/8: remove device info in error message when name is empty. Use else if
>> after call of bdrv_snapshot_find_by_id_and_name().
>>     Other:
>>     2/8: refined the comments in code for bdrv_snapshot_delete().
>>     3/8: in error reporting, change format from "reason is: '%s'" to
>> "reason is: %s".
>>
>> 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
>>
>>    block/qcow2-snapshot.c     |   55 +++++++---
>>    block/qcow2.h              |    5 +-
>>    block/rbd.c                |   21 ++++-
>>    block/sheepdog.c           |    5 +-
>>    block/snapshot.c           |  131 ++++++++++++++++++++++-
>>    blockdev.c                 |  190 ++++++++++++++++++++++++++++++++
>>    hmp-commands.hx            |   37 ++++++-
>>    hmp.c                      |   22 ++++
>>    hmp.h                      |    2 +
>>    include/block/block_int.h  |    5 +-
>>    include/block/snapshot.h   |   14 +++-
>>    include/qemu-common.h      |    3 +
>>    qapi-schema.json           |   65 +++++++++++-
>>    qemu-img.c                 |   11 ++-
>>    qmp-commands.hx            |  104 ++++++++++++++++--
>>    savevm.c                   |   32 +++---
>>    tests/qemu-iotests/056     |  259 ++++++++++++++++++++++++++++++++++++++++++++
>>    tests/qemu-iotests/056.out |    5 +
>>    tests/qemu-iotests/group   |    1 +
>>    19 files changed, 913 insertions(+), 54 deletions(-)
>>    create mode 100755 tests/qemu-iotests/056
>>    create mode 100644 tests/qemu-iotests/056.out
>>
>>
> Hello,
>    any comments for this version? I just found 056 is taken in
> upstream this morning, may respin if you like.
> 
  I guess it is hard to catch 1.6, so rebased on upstream and re-target
to 1.7.

-- 
Best Regards

Wenchao Xia