[Bug 1049994] New: Can't boot btrfs snapshot sent to then received from an external disk

http://bugzilla.opensuse.org/show_bug.cgi?id=1049994 Bug ID: 1049994 Summary: Can't boot btrfs snapshot sent to then received from an external disk Classification: openSUSE Product: openSUSE Tumbleweed Version: Current Hardware: Other OS: Other Status: NEW Severity: Normal Priority: P5 - None Component: Bootloader Assignee: jsrain@suse.com Reporter: antoine.belvire@opensuse.org QA Contact: jsrain@suse.com Found By: --- Blocker: --- I have the following usecase: I'd like to be able to put my Btrfs snapshots taken with snapper on an external disk and then send them back to the origin disk when needed to do a snapper rollback. Unfortunately, boot on a received snapshot does not work without some tweaks. This has been discussed at https://forums.opensuse.org/showthread.php/525877. Configuration: - openSUSE Tumbleweed, current version, probably the same for Leap - Default partitioning settings (Btrfs used for /, snapshots enabled) except there is not separate Xfs /home partition. - Installed in a vm Steps to reproduce: 1. Create a snapshot with snapper 2. Send the snapshot to an external disk: # mkdir -p /<id> # btrfs send /.snapshots/<id>/snapshot | btrfs receive /<id> # cp /.snapshots/<id>/info.xml /<id> 3. Delete the snapshot from origin disk 4. Send the backup snapshot from external disk to origin disk: # mkdir -p /.snapshots/<id> # btrfs send /<id>/snapshot | btrfs receive /.snapshots/<id> # cp /<id>/info.xml /.snapshots/<id> 5. Regenerate grub-snapshot.cfg: # /usr/lib/snapper/plugins/grub --refresh 6. Reboot and try to boot snapshot <id> Actual result: - Can't enter the menu of bootable snapshot <id>: The screen blinks and stays at the list of bootable snapshots. - Regular snapshots (i.e. not sent from another disk) can still be booted. Expected result: - Boot on snapshot <id> should be possible Workaround: There are two supplementary things to do: 1. Add the .snapshots folder to the received snapshot: # btrfs property set -t s /.snapshots/<id>/snapshot ro false # mkdir -p /.snapshots/<id>/snapshot/.snapshots # btrfs property set -t s /.snapshots/<i>/snapshot ro true 2. In grub, before trying to enter snapshot <id>, go to command line and do: grub> btrfs-mount-subvol ($root) /.snapshots @/.snapshots 3. Now you can enter the menu of snapshot <id> -- You are receiving this mail because: You are on the CC list for the bug.