[libvirt] [PATCH 4/9] Add support for encrypted (qcow) volume creation.

[Miloslav Trmac]

----- "Daniel P. Berrange" <berrange at redhat.com> wrote:

> On Tue, Jul 21, 2009 at 01:12:00PM +0200, Miloslav Trma?? wrote:
> > Supports only virStorageVolCreateXML, not
> virStorageVolCreateXMLFrom.
> > 
> > Curiously, qemu-img does not need the passphrase for anything to create
> > an encrypted volume.  This implementation is sufficient for the qcow2
> > format, and for other formats when all encryption parameters are
> > pre-specified.
> 
> I believe that qemu-img only requires the passphrase if it is going
> to actually write data blocks to the file. Thus creating an empty
> file doesn't need it, but in the code path which clones an existing
> file it would need it. eg, virStorageVolCreateXMLFrom() would need
> it if you had implemented that - indeed that would potentially need 
> both the source and destination keys.
Yes, that's correct.
    Mirek