[ovirt-users] Exporting VMs using cinder disks and importing ceph disks from cinder

[Nir Soffer]

On Thu, Jul 21, 2016 at 5:33 PM, Alessandro De Salvo
<Alessandro.DeSalvo at roma1.infn.it> wrote:
> Hi Nir,
>
> On Thu, 2016-07-21 at 17:25 +0300, Nir Soffer wrote:
>> On Thu, Jul 21, 2016 at 4:58 PM, Alessandro De Salvo
>> <Alessandro.DeSalvo at roma1.infn.it> wrote:
>> > Hi,
>> > I'm trying to export VMs using ceph disks on ovirt 4. The export itself
>> > works, but the disks are not saved in the export domains, only the VM
>> > definition is stored. Also, I cannot easily re-import them, unless I
>> > clone the VM instead of importing it, it just fails.
>> > Cinder itself can backup volumes, if instructed to do so.
>> > However, let's say I would like to export the machine from an ovirt
>> > infrastructure and load it into another one passing by the export domain
>> > and sharing the same underlying ceph cluster. I could easily load the VM
>> > from the export domain into the second ovirt infrastructure, but how can
>> > I define the disk, whose volume exists in the cinder instance, in the
>> > second ovirt? I do not see any obvious way to map an existing cinder
>> > volume into ovirt, without creating a new disk, which would not be
>> > helpful.
>> > As a consequence of all this, in case of problems with the disks, there
>> > is no way to recover them.
>> > Any help?
>>
>> We do not support copying, moving, or exporting disks to/from ceph yet.
>>
>> You can copy the disks manually from ceph using ceph command line
>> tools, and qemu-img should also handle them.
>
> Yes, I just found a trick to re-import the disk, using qemu-img to dump
> the image on a file from rbd:<pool>/<file>, create a new disk in ovirt
> and use qemu-img to copy it back on the new image. Technically it is
> working, but it's a bit convoluted. Any plans to add the relevant
> support in ovirt?

We want to support all operations available with legacy storage
with ceph. I don't know about plans to improve the situation for 4.1.

>> After you copy an image, you will a have a raw image that can be
>> uploaded to new ovirt disk from engine ui (new image upload feature).
>
> Are you talking to the upload button in the Disks tab? I do not see how
> I can upload to cinder/ceph from there.

Yes, upload to ceph is not supported yet, hopefully we can do this in
4.1.

Today you can upload to any other storage after you copied the
image our of ceph to a local file. This automates creation of a new
disk and copying the file into the new disk, which is more tricky if
you want to copy into block storage.

Nir