[Qemu-devel] Re: [PATCH v2 0/2] virtagent - fsfreeze support

[Michael Roth <mdroth@linux.vnet.ibm.com>]

Hi Jes,

Can you add Badari (CC'd) to the next round? He's looked at potentially 
using virtagent for snapshots in the past and might have some insights 
here. Thanks.

On 02/02/2011 02:42 AM, Jes.Sorensen@redhat.com wrote:
> From: Jes Sorensen<Jes.Sorensen@redhat.com>
>
> Hi
>
> This is a first attempt to add fsfreeze support to virtagent. The idea
> is for the guest agent to walk the list of locally mounted file
> systems in the guest, and issuing an ioctl to freeze them. The host
> can then do a live snapshot of the guest, obtaining stable file
> systems. After the snapshot, the host then calls the thaw function in
> virtagent, which goes through the list of previously frozen file
> systems and unfreezes them.
>
> The list walking ignores remote file systems such as NFS and CIFS as
> well as all pseudo file systems.
>
> The guest agent code is in the first patch, and host agent code is in
> the second patch. For now there is only human monitor support, but it
> should be pretty straight forward to add QMP support as well.
>
> Comments and suggestions welcome!
>
> v2 of the patch addresses the issues pointed out by Stefan and Michael.
>
> Cheers,
> Jes
>
>
> Jes Sorensen (2):
>    Add virtagent file system freeze/thaw
>    Add monitor commands for fsfreeze support
>
>   hmp-commands.hx    |   48 +++++++++++
>   virtagent-common.h |    9 ++
>   virtagent-server.c |  190 ++++++++++++++++++++++++++++++++++++++++++
>   virtagent.c        |  235 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>   virtagent.h        |    9 ++
>   5 files changed, 491 insertions(+), 0 deletions(-)
>