Re: [Qemu-devel] [RFC PATCH v3 00/11] qemu-ga: fsfreeze on Windows using VSS

[Libaiqing]

Hi,
  I tried the patch v3,with the following config.
  
  Guest os : win7 32bit professional
  Host os : fedora 17 
  Command: 
     qemu-kvm -enable-kvm -name win7 -M pc-0.15 -m 1024 -smp 2 -boot c  -device 
virtio-serial  -drive 
file=/home/libaiqing/vss/win7.img,if=virtio,index=0,format=qcow2 - -monitor 
stdio -vga qxl  -vnc :1 -chardev
     
socket,id=charchannel0,path=/var/lib/libvirt/qemu/wahaha1_requester,server,nowait
 -device 
virtserialport,chardev=charchannel0,id=channel0,name=org.qemu.guest_agent.0  
  Output:
     address@hidden ~]# socat stdio,ignoreeof 
unix-connect:/var/lib/libvirt/qemu/wahaha1_requester
     {"execute":"guest-fsfreeze-freeze"}
     {"return": 2}
     {"execute":"guest-fsfreeze-status"}
     {"return": "frozen"}
     {"execute":"guest-fsfreeze-thaw"}
     {"error": {"class": "GenericError", "desc": "DoSnapshotSet. (Error: 
8004230f) "}}
     {"execute":"guest-fsfreeze-status"}
     {"return": "thawed"}
     {"execute":"guest-fsfreeze-freeze"}
     {"return": 2}
     {"execute":"guest-fsfreeze-status"}
     {"return": "frozen"}
     {"execute":"guest-fsfreeze-thaw"}
     {"error": {"class": "GenericError", "desc": "DoSnapshotSet. (Error: 
80042314) "}}
     {"execute":"guest-fsfreeze-status"}
     {"return": "thawed"}

  Issue:
    1 Extcuting the command "guest-fsfreeze-thaw" failed,but the fs status is 
changed to thawed.Is this ok?
    2 Extcuting the command "guest-fsfreeze-thaw" twice,the desc is different 
each time.

  Could you give me some advise to debug this problem ? I can provide more 
information if need.

Regards,
baiqing
> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden On Behalf Of
> Tomoki Sekiyama
> Sent: Tuesday, May 21, 2013 11:34 PM
> To: address@hidden
> Cc: address@hidden; address@hidden;
> address@hidden; address@hidden; address@hidden;
> address@hidden
> Subject: [Qemu-devel] [RFC PATCH v3 00/11] qemu-ga: fsfreeze on Windows
> using VSS
> 
> Hi,
> 
> This patch series adds fsfreeze support for Windows qemu-guest-agent.
> 
> changes from v2:
>  - [06/11] Fix errors in Windows 7, reported by Li Baiqing
>            (see below for details).
> 
> changes from v1:
>  - Fix out-tree build by stop using recursive Makefile
>  - Added script to extract VSS SDK headers on POSIX systems using msitools
>    (thanks Paolo)
>  - Remove some unnecessary header files
> 
> v2: http://lists.gnu.org/archive/html/qemu-devel/2013-04/msg02518.html
> 
> 
> * Description
>   In Windows, VSS (Volume Shadow Copy Service) provides a facility to
>   quiesce filesystems and applications before disk snapshots are taken.
>   This patch series implements "fsfreeze" command of qemu-ga using VSS.
> 
> 
> * How to build & run qemu-ga with VSS support
> 
>  - Download Microsoft VSS SDK from:
>    http://www.microsoft.com/en-us/download/details.aspx?id=23490
> 
>  - Setup the SDK
>    scripts/extract-vsssdk-headers setup.exe (on POSIX-systems)
> 
>  - Specify installed SDK directory to configure option as:
>    ./configure -with-vss-sdk="path/to/VSS SDK"
> --cross-prefix=i686-w64-mingw32-
> 
>  - make qemu-ga.exe
> 
>  - Install qemu-ga.exe, qga/vss-win32-provider/qga-provider.{dll,tlb}, and
>    the other required mingw libraries into the same directory in guests
> 
>  - Run `qemu-ga.exe -s install' and `net start qemu-ga' in the guests
> 
> 
> * About errors in Windows 7 with patch v2
>   VSS requires to write to snapshot volumes just before making them read-only
>   at final commit phase. This feature is called `auto-recovery'
>   (See
> http://msdn.microsoft.com/en-us/library/windows/desktop/aa384651(v=vs.85)
> .aspx#base.vssgloss_auto_recoved_shadow_copy for details).
> 
>   Since qemu and libvirt don't have feature to handle writable snapshots,
>   this patchset just disables auto-recovery by specifying
>   VSS_VOLSNAP_ATTR_NO_AUTORECOVERY flag to SetContext.
>   Unfortunately, this flag seems unsupported in Windows 7 or earlier.
>   It tries to look up the snapshot volumes to write and fails in
>   VSS_E_OBJECT_NOT_FOUND.
> 
>   For fundamental resolution we need a framework for guests to query
> snapshots
>   and to mount them as writable snapshots, but we just ignore the error in
>   this patchset.
> 
> Any feedback are appliciated.
> 
> ---
> Tomoki Sekiyama (11):
>       configure: Support configuring c++ compiler
>       Fix errors and warnings while compiling with c++ compilier
>       Add a script to extract VSS SDK headers on POSIX system
>       qemu-ga: Add an configure option to specify path to Windows VSS SDK
>       qemu-ga: Add Windows VSS provider to quiesce applications on fsfreeze
>       qemu-ga: Add Windows VSS requester to quisce applications and
> filesystems
>       qemu-ga: call Windows VSS requester in fsfreeze command handler
>       qemu-ga: install Windows VSS provider on `qemu-ga -s install'
>       qemu-ga: Add VSS provider .tlb file in the repository
>       QMP/qemu-ga-client: make timeout longer for guest-fsfreeze-freeze
> command
>       QMP/qmp.py: set locale for exceptions to display non-ascii messages
> correctly
> 
> 
>  .gitignore                              |    1
>  Makefile                                |    3
>  Makefile.objs                           |    2
>  QMP/qemu-ga-client                      |    4
>  QMP/qmp.py                              |    4
>  configure                               |   59 ++++
>  hmp.c                                   |    2
>  hw/pci/pci.c                            |    2
>  qga/Makefile.objs                       |    7
>  qga/commands-win32.c                    |   74 ++++-
>  qga/main.c                              |   41 +++
>  qga/vss-win32-provider.h                |   26 ++
>  qga/vss-win32-provider/Makefile.objs    |   25 ++
>  qga/vss-win32-provider/install.cpp      |  494
> +++++++++++++++++++++++++++++++
>  qga/vss-win32-provider/provider.cpp     |  474
> ++++++++++++++++++++++++++++++
>  qga/vss-win32-provider/qga-provider.def |   10 +
>  qga/vss-win32-provider/qga-provider.idl |   20 +
>  qga/vss-win32-provider/qga-provider.tlb |  Bin
>  qga/vss-win32-requester.cpp             |  404
> +++++++++++++++++++++++++
>  qga/vss-win32-requester.h               |   31 ++
>  qga/vss-win32.h                         |   85 +++++
>  rules.mak                               |    9 +
>  scripts/extract-vsssdk-headers          |   25 ++
>  scripts/qapi.py                         |    9 +
>  24 files changed, 1796 insertions(+), 15 deletions(-)
>  create mode 100644 qga/vss-win32-provider.h
>  create mode 100644 qga/vss-win32-provider/Makefile.objs
>  create mode 100644 qga/vss-win32-provider/install.cpp
>  create mode 100644 qga/vss-win32-provider/provider.cpp
>  create mode 100644 qga/vss-win32-provider/qga-provider.def
>  create mode 100644 qga/vss-win32-provider/qga-provider.idl
>  create mode 100644 qga/vss-win32-provider/qga-provider.tlb
>  create mode 100644 qga/vss-win32-requester.cpp
>  create mode 100644 qga/vss-win32-requester.h
>  create mode 100644 qga/vss-win32.h
>  create mode 100755 scripts/extract-vsssdk-headers
>