Re: [libvirt] virStorageVolCreateXMLFrom
"Daniel P. Berrange" <berrange(a)redhat.com> wrote on
22/06/2009 12:08:39:
On Mon, Jun 22, 2009 at 09:59:00AM +0300, Kenneth Nagin wrote:
>
> I'd like to get a better understanding of the
virStorageVolCreateXMLFrom
> api Its name and signature imply that it is a cloning operation
that
copies
> a volume from one location to another. Is this correct?
Yes this method does a deep-copy of all the data, and can convert between
disk formats at the same time (eg raw -> qcow2, or any qemu-img format).
> Does it support remote copy of non-shared storage, e.g. from a http
server?
It only supports copying within the same storage pool at this time, and
we don't implement any storage pool based on http.
> Is there any thought about adding digest validation check, e.g. with a
md5
> digest?
What would that do ? Or rather what semantics would you want from such a
thing ? I rather hope that just reading & writing a local file would
not result in data corruption.
My question was in the context of supporting remote
copy (see above).
The digest validation would only be necessary if you supported remote copy.
> Is copy-on-write cloning supported in this command?
No, you can create copy on write volumes using the <backingStore> element
in the XML description
http://libvirt.org/formatstorage.html#StorageVolBacking
This is supported for LVM volumes, qcow, qcow2 and vmdk files at this
time.
Regards,
Daniel
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