On Tue, Dec 1, 2020 at 2:06 AM Sreyan Chakravarty <sreya...@gmail.com> wrote: > > > > On Mon, Nov 30, 2020 at 10:12 PM Chris Murphy <li...@colorremedies.com> wrote: >> >> >> I don't understand why you're going to another forum to ask the same >> question, and posting different information. It's just making it more >> difficult to provide answers. Here is what you posted there: >> > > Since I did not know about BTRFS. > >> >> $ btrfs subvolume list / >> ID 256 gen 3794 top level 5 path fedora >> ID 264 gen 2296 top level 256 path root/snapshots/test >> >> That is not a default subvolume layout for Fedora 33. I have no idea >> how you arrived at this layout but it's not the default. If you do a >> default (automatic) installation of Fedora 33, you will have two >> subvolumes: home and root, at the top level. > > > Ok, I have managed to get BTRFS snapshots working. > > I must have messed up the installation somehow. Now I have a subvolume under > the toplevel volume which I can now rename. > > But the problem is that I have to reboot to a live CD just to take a snapshot.
No you don't. > Any way to do it within the OS ? I gave an explicit, line by line example, in this thread, two days ago. The unintuitive part of that particular example, is mounting the top-level of the file system. If you have a default Fedora 33 installation, this can be done by mounting the main volume (the device+partition listed in 'df' for both / and /home) to something like /mnt or wherever else you prefer. And now you will see what look like directories named "root" and "home" - but those are subvolumes. And you can snapshot them. Keeping all subvolumes and snapshots in this normally hidden top-level is referred to as the "flat" layout. https://btrfs.wiki.kernel.org/index.php/SysadminGuide#Layout In the "nested" layout, you don't have to mount the top-level, you can just directly snapshot the mountpoint. e.g. btrfs subvolume snapshot /home /home/home.snapshot1 That will snapshot the "home" subvolume that is mounted at /home, and place it in /home with the name home.snapshot1. The reason it's referred to as "nested" layout is because these subvolume snapshots appear to be located within the subvolume you just just snapshot. As a consequence of this, if you 'du /home' it will add up all of the stuff in /home two times. Once for the "home" subvolume and again for the "home.snapshot1" subvolume snapshot. It doesn't know that one of them is a snapshot, nor that you'd want to exclude one of them from the usage calculation. Hence 'btrfs filesystem du -s /path/' which provides more information. Another example: btrfs subvolume snapshot / /root.snapshot This will snapshot the "root" subvolume that is mounted at /, and place it /, with the name root.snapshot1. Btrfs snapshots are not on rails. It will let you create a snapshot anywhere. Another set of examples: btrfs subvolume snapshot /home /root/home.snapshot btrfs subvolume snapshot / /home/ I'm not sure why anyone would organize snapshots that way, but btrfs doesn't care, it'll let you do it. -- 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
