Re: [Libguestfs] missing btrfs subvol support

On Fri, Oct 10, Olaf Hering wrote: > Is btrfs subvol support failing just for me? This is an old thread, and it seems the underlying bug is not fixed because guestfs takes the wrong approach, IMO. >From how I understand btrfs, it has the concept of subvolumes. Each one is an entry point for a separate filesystem. In addition to that it has a default subvol which is used if no specific subvolume is specified. This turns the whole btrfs partition (or assembled blockdevice) into a container of individual filesystems. But guestfs, as far as I understand it, just mounts the btrfs filesystem with the default subvolume and ends up somewhere. Then it tries to make sense of the other subvolumes based on info from a /etc/fstab, which may or may not exist. This looks like the wrong approach. Shouldnt it instead handle the whole thing as a container, just as it does for an individual disk? First do something like mount subvolid=0, poke around there and collect the items (sub list -a). Then use all this info to see which one might be one of the many root filesystems?