Disclaimer: I only have limited experience with btrfs and never used it for root partition.
On Thu, Oct 28, 2021 at 04:10:08 +0100, piorunz wrote: > I have / partition on btrfs subvolume, default name @rootfs created by > Debian. > [...] > > Question: > How can I rename / subvolume on btrfs from @rootfs to @? If it doesn't move to another parent folder, just `mv`ing it is the correct approach afaik. > I tried: > rename folder name by hand from USB stick Linux Mint from @rootfs to @, > and then changing @rootfs to @ in /etc/fstab, but grub didn't booted, it > thrown me out to grub emergency console. I had to revert it back. Maybe the grub command for booting also explicitly specifies the subvolume. Can you take a look at the relevant line in /boot/grub/grub.cfg? (If you're not sure what to look at, serach for the text of the netry you use in the GRUB-menu, everything from there until a line starting with `initrd` could possibly be relevant). If yes, you'll need to change that in /etc/default/grub and/or /etc/default/grub.d/* and then run update-grub as root. > Some context: > $ sudo btrfs subvolume list / > ID 256 gen 176714 top level 5 path @rootfs > ID 265 gen 21191 top level 256 path var/lib/portables > ID 266 gen 21192 top level 256 path var/lib/machines What does `sudo btrfs subvolume get-default /` tell you before _and_ after you renamed the subvolume? If it was @rootfs before but is not @ afterwards, you'll need to set the default using sudo btrfs subvolume set-default ...
