[Qemu-devel] Qemu snapshot mode: /tmp/vl.xxx file missing?

[Qemu-devel] Qemu snapshot mode: /tmp/vl.xxx file missing?

[Atoosah]

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When using the -snapshot mode of Qemu, shouldn't the vl.xxx file that is
created be visible in the host /tmp directory?

I use the command: $qemu -snapshot -hda disk_image.img -m 256

which seems to write the file to /tmp/vl.xxx where xxx is some random
filename chosen by Qemu during every boot (I see this by commenting
[QEMU_PATH]/block.c I'm using a modified version of qemu-0.8.2 on a Linux
machine, but I also can't find the vl.xxx file that's created using
qemu-0.9.0.

In the documentation, it says that when using snapshot mode "When sectors in
[misspelling] in written, they are written in a temporary file created in
'/tmp'..." but i cannot see the file that is supposedly created on the host
directory /tmp (or in QEMU_PATH directory). Where is Qemu actually writting
to in snapshot mode, before commit ever occurs?

Any suggestions and ideas would be helpful.

thank you,
Atoosaah

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Re: [Qemu-devel] Qemu snapshot mode: /tmp/vl.xxx file missing?

[Mulyadi Santosa]

On Tue, Aug 11, 2009 at 11:53 PM, Atoosah<atoosaah@gmail.com> wrote:
> When using the -snapshot mode of Qemu, shouldn't the vl.xxx file that is
> created be visible in the host /tmp directory?

IIRC, the trick is to create (open) the file and write to it...but
Qemu also unlink it as soon as it is created.

This way, the file become invisible but still accessible until Qemu close it

You might want to read "man 2 unlink" for further explanation.

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer
blog: the-hydra.blogspot.com

Re: [Qemu-devel] Qemu snapshot mode: /tmp/vl.xxx file missing?

[Atoosah]

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Thank you! Found the deleted file via "lsof" command.
-Atoosaah


On Wed, Aug 12, 2009 at 12:47 AM, Mulyadi Santosa <mulyadi.santosa@gmail.com
> wrote:

> On Tue, Aug 11, 2009 at 11:53 PM, Atoosah<atoosaah@gmail.com> wrote:
> > When using the -snapshot mode of Qemu, shouldn't the vl.xxx file that is
> > created be visible in the host /tmp directory?
>
> IIRC, the trick is to create (open) the file and write to it...but
> Qemu also unlink it as soon as it is created.
>
> This way, the file become invisible but still accessible until Qemu close
> it
>
> You might want to read "man 2 unlink" for further explanation.
>
> --
> regards,
>
> Mulyadi Santosa
> Freelance Linux trainer
> blog: the-hydra.blogspot.com
>

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Re: [Qemu-devel] Qemu snapshot mode: /tmp/vl.xxx file missing?

[Mulyadi Santosa]

On Tue, Aug 18, 2009 at 2:57 AM, Atoosah<atoosaah@gmail.com> wrote:
>
> Thank you! Found the deleted file via "lsof" command.

You're welcome. Yep, lsof should reveal it....

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer
blog: the-hydra.blogspot.com