booting R/O snapshots on Ubuntu

[jfabernathy]

I have added snapper and grub-btrfs to a Kubuntu 22.04 system and manage the snapshots with btrfs-assistant. This system does not have subvols @var or @cache. Just @, @home, and @/.snapshots. So I can't boot any of the snapshots. The workaround with the overlayfs mentions Archlinux. What about Ubuntu based O/S's?

I guess I could boot a USB install ISO and restore those snapshots manually??

[jfabernathy]

I went back and created subvolumes @var, @log, and @tmp. Then moved that content from under @ to the respective subvols. But that doesn't help booting the snapshots. So I'm going to need the overlayfs.

[avpariy]

On last Ubuntu Lunar i can change btrfs snapshot from read-only to read-write and all boot ok from snapshot. This can be done from btrfs assistant o manually from shell: sudo btrfs property get -ts /.snaphots/10 and then set it to rw type.

You can check it with:

$ sudo btrfs property get -ts /path/to/snapshot/

If it returns ro=true, you have to make it writable with:

$ sudo btrfs property set -ts /path/to/snapshot/ ro false

may be this helpfull to integrate workaround in grub-btrfs