I'm intending to make individual directories snapshotable in order to be able to experiment and rollback. Since there are many such directories and their contents can vary in size, solutions such as LVM or ZFS are not well-suited as they require to re-partition existing systems. A much more flexible solution apears to be to use qcow2 files that are then mounted into the working directories. They allow sparsity and snapshots, including consolidating snapshots into base layers. While these features are implemented by LVM as well, using qcow2 files would be the easiest to deploy on existing systems.
The idea is to use guestfs or ndb to mount a qcow2 file into the target directory for every dir that needs it. The last missing puzzle piece is how to make this boot-proof. I've been looking for ways to get guestfs or ndb into fstab but I cannot find any literature. Maybe I am searching for the wrong thing (is my idea bad altogether - if so, for what reasons?).
How can I mount local qcow2 files upon boot?
