[Qemu-devel] [help] QEMUFile's format

[Qemu-devel] [help] QEMUFile's format

[¤終於aware]

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Hi,
     Is anyone clear about the format of qemu file for savevm or loadvm?
     
 bruce

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[help] QEMUFile's format

[¤終於aware]

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Hi,
     Is anyone clear about the format of qemu file for savevm or loadvm?
     
 bruce

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Re: [Qemu-devel] [help] QEMUFile's format

[Shu Ming]

Do you mean the file format? qcow2, qed, raw? Or the content layout in 
the file image?
On 2011-12-23 13:17, ¤終於aware wrote:
> Hi,
> Is anyone clear about the format of qemu file for savevm or loadvm?
> bruce


-- 
Shu Ming<shuming@linux.vnet.ibm.com>
IBM China Systems and Technology Laboratory

Re: [help] QEMUFile's format

[Shu Ming]

Do you mean the file format? qcow2, qed, raw? Or the content layout in 
the file image?
On 2011-12-23 13:17, ¤終於aware wrote:
> Hi,
> Is anyone clear about the format of qemu file for savevm or loadvm?
> bruce


-- 
Shu Ming<shuming@linux.vnet.ibm.com>
IBM China Systems and Technology Laboratory

Re: [Qemu-devel] [help] QEMUFile's format

[陳韋任]

On Fri, Dec 23, 2011 at 01:32:50PM +0800, Shu Ming wrote:
> Do you mean the file format? qcow2, qed, raw? Or the content layout in 
> the file image?
> On 2011-12-23 13:17, ¤終於aware wrote:
> > Hi,
> > Is anyone clear about the format of qemu file for savevm or loadvm?
                                                  ^^^^^^^^^^
  savevm requires image's format to be qcow2.

  You can check http://en.wikipedia.org/wiki/Qcow for more information.

Regards,
chenwj
   
-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj

Re: [Qemu-devel] [help] QEMUFile's format

[陳韋任]

>   savevm requires image's format to be qcow2.
> 
>   You can check http://en.wikipedia.org/wiki/Qcow for more information.

  Plus this,
  http://www.linux-kvm.org/wiki/images/6/63/2011-forum-qcow2.pdf

HTH, 
chenwj

-- 
Wei-Ren Chen (陳韋任)
Computer Systems Lab, Institute of Information Science,
Academia Sinica, Taiwan (R.O.C.)
Tel:886-2-2788-3799 #1667
Homepage: http://people.cs.nctu.edu.tw/~chenwj

Re: [Qemu-devel] [help] QEMUFile's format

[Dong Xu Wang]

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You could have a look at docs/specs directory.

2011/12/23 陳韋任 <chenwj@iis.sinica.edu.tw>

> On Fri, Dec 23, 2011 at 01:32:50PM +0800, Shu Ming wrote:
> > Do you mean the file format? qcow2, qed, raw? Or the content layout in
> > the file image?
> > On 2011-12-23 13:17, ¤終於aware wrote:
> > > Hi,
> > > Is anyone clear about the format of qemu file for savevm or loadvm?
>                                                   ^^^^^^^^^^
>  savevm requires image's format to be qcow2.
>
>  You can check http://en.wikipedia.org/wiki/Qcow for more information.
>
> Regards,
> chenwj
>
> --
> Wei-Ren Chen (陳韋任)
> Computer Systems Lab, Institute of Information Science,
> Academia Sinica, Taiwan (R.O.C.)
> Tel:886-2-2788-3799 #1667
> Homepage: http://people.cs.nctu.edu.tw/~chenwj
>
>

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Re: [Qemu-devel] [help] QEMUFile's format

[Stefan Hajnoczi]

On Fri, Dec 23, 2011 at 01:17:00PM +0800, ¤終於aware wrote:
>      Is anyone clear about the format of qemu file for savevm or loadvm?

If you are interested in the serialized device state format (e.g. the
e1000 NIC's serialized state) then the answer is no.  I'm not aware of
any specification or schema that documents the device state.

It has been known to change in the past and writing tools that depend on
a specific device state layout outside of qemu.git is not viable today
because you'll have to watch qemu.git hw/ code changes and update your
external code every time something changes.  It seems like a bad idea to
duplicate the device state layout outside of qemu.git.

For a temporary hack, read the QEMUFile and hw/ save/load code.  You can
try qemu-io -c "read -b 0 $length" to extract the vmstate from a qcow2
image file.

Stefan

Re: [help] QEMUFile's format

[Stefan Hajnoczi]

On Fri, Dec 23, 2011 at 01:17:00PM +0800, ¤終於aware wrote:
>      Is anyone clear about the format of qemu file for savevm or loadvm?

If you are interested in the serialized device state format (e.g. the
e1000 NIC's serialized state) then the answer is no.  I'm not aware of
any specification or schema that documents the device state.

It has been known to change in the past and writing tools that depend on
a specific device state layout outside of qemu.git is not viable today
because you'll have to watch qemu.git hw/ code changes and update your
external code every time something changes.  It seems like a bad idea to
duplicate the device state layout outside of qemu.git.

For a temporary hack, read the QEMUFile and hw/ save/load code.  You can
try qemu-io -c "read -b 0 $length" to extract the vmstate from a qcow2
image file.

Stefan