On Thu, Jul 7, 2016 at 2:17 PM, Kai Herlemann <nesa...@freenet.de> wrote: > Hi, > > I want to rollback a snapshot and have done this by execute "btrfs sub > set-default / 618". maybe just a typo here, command syntax is: # sudo btrfs sub set-default btrfs subvolume set-default: too few arguments usage: btrfs subvolume set-default <subvolid> <path>
Set the default subvolume of a filesystem > Now I want to delete the old top volume to save space, but google and > manuals didn't helped. > > I mounted for the following the root volume at /mnt/gparted with subvolid=0, > subvol=/ has the same effect. > Usually, the top volume is saved in /@, so I would be able to delete it by > execute "btrfs sub delete /@" (or move at first @ to @_badroot and the > snapshot to @). But that isn't possible, the output of that command is > "ERROR: cannot access subvolume /@: No such file or directory". > I've posted the output of "btrfs sub list /mnt/gparted" at > http://pastebin.com/r7WNbJq8. As you can see, there's no subvolume named @. I think one or the other commandtyping didn't have its expected effect, just to make sure I get the right state, can you do: mkdir -p /fsroot mount -o subvolid=0 UUID=<uuid of filesystem> /fsroot btrfs sub list /fsroot btrfs subvolume get-default / What the latest debian likes as naming convention I dont know, but in openSuSE @ is a directory in the toplevel volume (ID=5 or ID=0 as alias) and that directory contains subvolumes. You can do whatever you like best, but at least make sure you have mount entries in fstab subvolumes like var/cache/apt and usr/src, otherwise this magnificent rootfstree snapshotting gets you into trouble. I think your current default subvolume is still 5, so you would need: fstab: UUID=<uuid of filesystem> / btrfs defaults 0 0 #UUID=<uuid of filesystem> /home btrfs defaults,subvol=@/home 0 0 UUID=<uuid of filesystem> /usr/src btrfs defaults,subvol=@/usr/src 0 0 UUID=<uuid of filesystem> /var/cache/apt btrfs defaults,subvol=@/var/cache/apt 0 0 UUID=<uuid of filesystem> /.snapshots btrfs defaults,subvol=@/.snapshots 0 0 UUID=<uuid of filesystem> /fsroot btrfs noauto,subvolid=0 0 0 mkdir -p /fsroot mount -o subvolid=0 UUID=<uuid of filesystem> /fsroot mkdir -p /usr/src mkdir -p /var/cache/apt mkdir -p /.snapshots mkdir -p /fsroot/@/usr mkdir -p /fsroot/@/var/cache btrfs sub create /fsroot/@/usr/src btrfs sub create /fsroot/@/var/cache/apt btrfs sub create /fsroot/@/.snapshots #snapshots might need different, the proposed one works at least for snapper btrfs sub snap / /fsroot/@/latestrootfs btrfs sub set-default <ID of /fsroot/@/latestrootfs> / btrfs fi sync / #for home fs is it similar as for root fs reboot You can then when you want rollback, set a snapshot to rw (or rename latestrootfs, snapshot snapshot to that name ) and make it default subvol and reboot (or maybe also do some temp chroot tricks, I have not tried that) > I have the same problem with my /home/ partition. > > Output of "uname -a" (self-compiled kernel): > Linux debian-linux 4.1.26 #1 SMP Wed Jun 8 18:40:04 CEST 2016 x86_64 > GNU/Linux > > Output of "btrfs --version": > btrfs-progs v4.5.2 > > Output of "btrfs fi show": > Label: none uuid: f778877c-d50b-48c8-8951-6635c6e23c61 > Total devices 1 FS bytes used 43.70GiB > devid 1 size 55.62GiB used 47.03GiB path /dev/sda1 > > Output of "btrfs fi df /": > Data, single: total=44.00GiB, used=42.48GiB > System, single: total=32.00MiB, used=16.00KiB > Metadata, single: total=3.00GiB, used=1.22GiB > GlobalReserve, single: total=416.00MiB, used=0.00B > > Output of dmesg attached. > > Thank you, > Kai > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
