On Tue, May 29, 2018 at 10:43 PM Eric Blake <ebl...@redhat.com> wrote:
> On 05/28/2018 05:27 AM, Arik Hadas wrote: > ... > > Few months ago people from the oVirt-storage team checked the qemu > toolset > > and replied that this capability is not yet provided, therefore we > > implemented the workaround described above. Apparently, the desired > ability > > can also be useful for the flow discussed in this thread so it worth > asking > > for it again :) > > You CAN get a logically collapsed view of storage (that is, what the > guest would see), by using an NBD export of volume V. Reading from that > volume will then pull sectors from whichever portion of the chain you > need. You can use either qemu-nbd (if no guest is writing to the > chain), or within a running qemu, you can use nbd-server-start and > nbd-server-add (over QMP) to get such an NBD server running. NBD expose the guest data, but we want the qcow2 stream - without creating a new image. Nir
