Re: [libvirt PATCH 07/20] qemu_snapshot: introduce qemuSnapshotCreateQcow2Files
On Mon, Mar 13, 2023 at 16:42:08 +0100, Pavel Hrdina wrote:
Extract creation of qcow2 files for external snapshots to separate
function as we will need it for external snapshot revert code.
Hmm, I don't think I like where this is going. I presume you want to use
this code to create the new overlay images.
If you want to use this also in cases where the VM was live you might
run into scenarios where the qemu-img code will not be able to handle
the overlay creation, specifically on networked storage.
I think we'll need to create the overlay images as part of the startup
of the reverted VM via QMP exactly as we are creating overlays currently
for snapshots.
Even when today's API will not allow reversion of non-local snapshots (I
didn't check further in this series yet) I don't think we should go the
way of using qemu-img at all.