On Sun, Nov 29, 2020 at 9:52 AM Sreyan Chakravarty <sreya...@gmail.com> wrote: > > Hi, > > I have only 1 partition, which has my root and /home together. > > I have installed Fedora33 with the default BTRFS settings, in which it does > not create a subvolume for root.
It does. You can check with any or all of these commands: mount | grep btrfs sudo btrfs subvolume list -t / cat /etc/fstab > I have created a snapshot of my entire root filesystem using: > > sudo btrfs subv snapshot / /root/snapshots/test > > Now what do I do ? > > How do I restore the snapshot ? There's a lot more than one way to do this. As one possible example: $ sudo mount /dev/nvme0n1p7 /mnt $ cd /mnt $ ls -li total 0 256 dr-xr-xr-x. 1 root root 1330 Nov 26 23:25 boot 256 dr-xr-xr-x. 1 root root 1966 Nov 23 22:43 boot.20201126 256 drwxr-xr-x. 1 root root 10 Jul 27 12:22 home 256 drwxr-xr-x. 1 root root 10 Jul 27 12:22 home.20201126-2 256 drwxr-xr-x. 1 root root 26 Nov 1 13:05 images 256 dr-xr-xr-x. 1 root root 132 Nov 5 18:23 root 256 dr-xr-xr-x. 1 root root 132 Nov 5 18:23 root.20201126 These are all subvolumes, as evidence by (a) it's a Btrfs file system, and (b) each has inode 256. Some folks like to put a character in the name of their subvolumes to indicate it's a subvolume, common is using the @ character. So @home and @root. I don't use this convention myself, I just stick only subvolumes in the "top-level" of the file system as you see here. The other convention I use is I make read-only snapshots with a date. What I do for a rollback is: # mv root rootold # btrfs sub snap root.20201126 root # reboot What this does is mounts the "top-level" [1] so you have direct access to the root and home subvolumes. And then rename the current root to something else; and then snapshot the desired snapshot as the new root. I do it this way because I don't have to modify either fstab or GRUB, both of which are expecting a subvolume named "root". You do not need to worry about renaming an active/in-use subvolume. Internally Btrfs is using subvolume ID's anyway, and that won't change. You'll notice if you rename a mounted subvolume, its name is immediately updated, verify this with the mount command before and after renaming. An alternative approach is a bit advanced only in that it requires knowing about the "default subvolume". And to give a complete answer is a bit of a story. But you can get the gist from 'man btrfs subvolume' and read the set-default and get-default sections in particular. [1] Nested versus flat layouts. The above example is a flat layout. https://btrfs.wiki.kernel.org/index.php/SysadminGuide#Layout -- Chris Murphy _______________________________________________ users mailing list -- users@lists.fedoraproject.org To unsubscribe send an email to users-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/users@lists.fedoraproject.org
