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

[Wenchao Xia]

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