Re: [Qemu-devel] from which version qemu support clone on rbd

[Brian Jackson]

On Wednesday, July 2, 2014 8:12:17 PM CDT, yue wrote:
> could you tell me why 'Qemu doesn't handle that level of abstraction'?
> i know qcow2 well, you can tell me the comparation。


Qemu would have to have a lot of extra code (that already exists elsewhere) 
to support taking snapshots/clones/etc of every backend device it supports. 
In the case of qcow2, the support exists because of the whole system 
snapshotting feature. Otherwise it's "bloat" that Qemu doesn't normally 
handle (it's left to the management layers above to handle).

--Iggy


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> At 2014-07-02 11:36:12, "Brian Jackson" <address@hidden> wrote:
> > Qemu doesn't handle that level of abstraction. The closest approximation 
> > you could probably come up with is qemu-img's backing file support for 
> > qcow2 images.
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> > You should stick to using the rbd tool to create clones of rbd devices. 
> > Alternatively, use a higher level tool (like openstack, etc) that  ...