Re: [Qemu-devel] [RFC PATCH 0/2] live backup vm

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

于 2012-12-7 18:12, Dietmar Maurer 写道:
> We already have a full functional implementation to create live snapshots including VM state.
>
> The interface allows you to create internal snapshots, or use external tools to create the blockdev snapshots
> directly on the underlying storage (we use that with nexenta). VM state is stored directly on a block device.
>
> https://git.proxmox.com/?p=pve-qemu-kvm.git;a=blob;f=debian/patches/internal-snapshot-async.patch;h=6c86de3a6160c58d77baa41a7774c4a80e63639e;hb=HEAD
>
> Unfortunately I had no time to cleanup those patches.
>
> - Dietmar
>
   have that patch been sent to mail-list? I'll rebase that patch
and take it as part of the API's implemention, if you agree.


>>    This patch is a scratch which enables a full live backup of VM, actually it is
>> equal to savevm lively. As a test it uses hmp command migrate to trigger the
>> action.
>>
>>    The ultimate goal is providing another command to user as:
>> snapshotvm [with_state] [internal] [live] which then create vm backups with
>> a screen image(I am not sure if a screen snapshot is supported in qemu
>> now). This function is enabled in VMWARE which can automatically create
>> full vm snapshots lively with a screen image which seems cool, so I want to
>> introduce it to qemu.
>>
>> Limitations:
>>    currently only implemented "snapshotvm with_state internal live" case.
>>    no screen captured in the time of creating snapshots.
>>    no good integration with existing savevm, migration, snapshot_blkdev code.
>>    no test case yet.
>>    hmp/qmp API not added.
>>
>>    Although there are so many gaps, but I want to send these patch first to
>> make sure I am in the right direction, esp the implemention of savevm lively
>> with vmstate, to see if there is potentional problem, such as creating
>> snapshots takes too long? Other cases would be simpler if this case have no
>> major problem found.
>>
>> Wenchao Xia (2):
>>    live backup vm, export functions
>>    live backup vm, snapshots all lively
>>
>>   block.c         |   21 ++++++
>>   block.h         |    2 +
>>   buffered_file.c |  106 +++++++++++++++++++++++++++
>>   buffered_file.h |    1 +
>>   migration.c     |  215
>> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>   migration.h     |   13 ++++
>>   savevm.c        |   37 +++-------
>>   sysemu.h        |    2 +
>>   8 files changed, 371 insertions(+), 26 deletions(-)
>>
>>
>
>
>


-- 
Best Regards

Wenchao Xia