Can't get btrfs-snap to work on Arch Linux

[C0rn3j]

Using btrfs-snap 1.7.3 from AUR.

[0] % pacman -Q btrfs-progs btrfs-snap
btrfs-progs 4.13-1
btrfs-snap 1.7.3-1

Maybe I'm misunderstanding how this tool works?

c0rn3j@Lappy : ~
[1] % sudo btrfs-snap /var/lib/machines hourly 24 
ERROR: /var/lib/machines is not a btrfs mountpoint (or old version of btrfs-tools, try > 0.19)

c0rn3j@Lappy : ~
[1] % sudo btrfs-snap / hourly 24     
btrfs subvolume show: too few arguments
usage: btrfs subvolume show [options] <subvol-path>|<mnt>

    Show more information about the subvolume

    -r|--rootid   rootid of the subvolume
    -u|--uuid     uuid of the subvolume

    If no option is specified, <subvol-path> will be shown, otherwise
    the rootid or uuid are resolved relative to the <mnt> path.

ERROR:  is not a btrfs mountpoint (or old version of btrfs-tools, try > 0.19)

c0rn3j@Lappy : ~
[1] % sudo btrfs subvolume show /
/
	Name: 			<FS_TREE>
	UUID: 			-
	Parent UUID: 		-
	Received UUID: 		-
	Creation time: 		-
	Subvolume ID: 		5
	Generation: 		42061
	Gen at creation: 	0
	Parent ID: 		0
	Top level ID: 		0
	Flags: 			-
	Snapshot(s):
				var/lib/machines
				test

[rprofijt]

Same issue here, according to the btrfs-progs changelog there were some changes in version 4.13.2 on the subvol list formatting: https://btrfs.wiki.kernel.org/index.php/Changelog#btrfs-progs_v4.13.2_.28Oct_2017.29

[HeinzApfel]

Looking into the script you'll find:

Remove trailing slash

mp=${1%/}

Therefore "/" goes to nothing. That's why "btrfs subvolume show $mp" gets no argument for the mountpoint.

Try "btrfs-snap -r // 15m 50" instead. Works for me on Debian 9 with btrfs-progs v4.13.3