[sheepdog-users] Problem with qcow2

[Cristian Del Carlo]

Hi Hitoshi,

Thanks for your response and for your time.
Correct me if I'm wrong.

I thought about using qcow2 to use qemu to have the ability to use internal
shapshot.

To have a consistent image of my virtual machines using sheepdog, I think I
should turn off the virtual machine, then make the snapshot ( dog vdi
snapshot -s ) and then turn it on again.

Using internal snapshot feature of qcow2/qemu I could avoid switching off
the machine.

External snapshot do not seem to be supported with sheepdog:

# virsh snapshot-create-as test3 test3-backup --disk-only --atomic

error: unsupported configuration: source for disk 'vda' is not a regular
file; refusing to generate external snapshot name

I'm thinking correctly or i am wrong?

Thanks,

2016-09-29 7:45 GMT+02:00 Hitoshi Mitake <mitake.hitoshi at gmail.com>:

>
>
> On Wed, Sep 28, 2016 at 12:41 AM, Cristian Del Carlo <cristian.delcarlo@
> targetsolutions.it> wrote:
>
>> Hi list,
>>
>> sorry if i have another question.
>>
>> I use sheepdog v0.9.3 and libvirt 1.2.17.
>> I have problems with qcow2.
>>
>> I create the image with the command:
>> qemu-img create -f qcow2 -o preallocation=metadata sheepdog:test2.qcow2
>> 20G
>>
>> After the command i can check the image:
>>
>> # qemu-img info sheepdog:///test2.qcow2
>> image: sheepdog:///test2.qcow2
>> file format: qcow2
>> virtual size: 20G (21474836480 bytes)
>> disk size: unavailable
>> cluster_size: 65536
>> Format specific information:
>>     compat: 1.1
>>     lazy refcounts: false
>>
>> But when i start to install a linux vm ( with virtmanager 1.3.2 ) if i
>> repeat the command i have the following :
>>
>> # qemu-img info sheepdog:///test2.qcow2
>> image: sheepdog:///test2.qcow2
>> file format: raw
>> virtual size: 20G (21478375424 bytes)
>> disk size: unavailable
>>
>> Even with "qemu-img convert" i have problem and i can work only with raw
>> file.
>>
>> Where is the problem?
>>
>
> What is the motivation of using qcow2 format on sheepdog virtual block
> device? It is a very rare use case so the functionality would have bugs. If
> it is critical for you, could you open an issue on github?
>
> Thanks,
> Hitoshi
>
>
>>
>> I would like to use qcow2 to have the possibility to use the command
>> "virsh snapshot-create --live vm".
>>
>> Thanks.
>>
>> Best regards,
>>
>>
>> *Cristian Del Carlo*
>>
>>
>> --
>> sheepdog-users mailing lists
>> sheepdog-users at lists.wpkg.org
>> https://lists.wpkg.org/mailman/listinfo/sheepdog-users
>>
>>
>


-- 


*Cristian Del Carlo*

*Target Solutions s.r.l.*

*T* +39 0583 1905621
*F* +39 0583 1905675
*@* cristian.delcarlo at targetsolutions.it

http://www.targetsolutions.it
P.IVA e C.Fiscale: 01815270465  Reg. Imp. di Lucca
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