This is likely answerable only by @tripleh or the dev team, as I see no mention of using the Qubes storage callback driver on web searches, other than in the GitHub repo.
I’m considering using the callback driver to support ephemerally or permanently encrypted AppVMs, when the template is in the primary pool and isn’t encrypted but the AppVM may have some snapshot components that aren’t in the same VG.
What’s the best way to start experimenting with the callback driver? Put a logging call in the cmd config parameter to see what calls are being made to see if it is feasible? E.g. I’m not sure if callback has visibility into volume paths or the ability to change the volume path used by the backend driver.
[Plan is to do dm-snapshot from the template. Unlike lvm-thin external-origin snapshots which must share a VG with the source, dm-snapshot origin can exist anywhere on the system.]
B