LINBIT
[Feature-Request] Snapshot shipping for file_thin (xfs)
Hi,
Related to https://github.com/piraeusdatastore/piraeus-operator/issues/553. Shipping is only supported on LVM / ZFS backed volumes according to the doc because they're the only ones that support snapshots, but file_thin when using XFS also does as far as I know. When I try to setup shipping on it however, it fails because it's unsupported by linstor. Any chance this could be implemented ?
I understand file thin isn't meant for production, but when using Talos on intel NUCs file_thin is the only method to get linstor going that does not break the upgrade path, and for home use in general it's a great option to have IMHO.
I image what's missing is the incremental send/recv for FILE and FILE_THIN.
It would be possible to do by keeping the base snapshot in the filesystem and comparing physical addresses of the succesive snapshots with the FIEMAP ioctl (see the filefrag utility for example). However this sounds very tricky to get right when there's anything else in the filesystem messing with reference links (a deduplicator, or another snapshot running concurrently.
While incremental backups are nice, they are not really a necessity, it would be enough for me to be able to ship only whole snapshots of FILE backed volumes.
