[libvirt] RFE storage cloning across connections.

[Daniel P. Berrange]

On Sun, Sep 13, 2009 at 10:08:48PM +0000, "J?hann B. Gu?mundsson" wrote:
> Virt-manager now supports migration and VM cloning however cloning only 
> works within a connection though so you can't clone to another machine. It 
> certainly would be a nice addition if supports storage cloning across 
> connections.

To support cloning between machines would essentially require the client
app to download the entire storage volume over one connection and upload
it over the second. I don't really much like this as an idea, although
our new data streaming APIs would make it fairly easy to add.

For somes types of pool, virt-manager could in fact do cloning between
machines / connections, without needing API support. eg, if using an
iSCSI pool, a SCSI FibreChannel, a NFS / GFS / GlusterFS pool these
are all shared storage mechanism. virt-manager ought to be able to 
work out that pool X on one connection, is the same as pool Y on the
second connection, and thus just do the clone completely within pool X
and just refresh pool Y to see the new volume.    If the source pool
is tied to the local machine (eg local disk, LVM, non-network FS),
then it could go via a second networked pool that is shared. 

Ultimately I think that if someone has more than a handful of hosts 
running virtualization, then it is very likely that they have got
networked/multi-host-accessible storage of some kind which would allow
for cross-connection cloning without this being needed in libvirt API
directly

Regards,
Daniel
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