xbian@xbian ~ $ sudo btrfs-auto-snapshot xbiancopy /dev/mmcblk0p2 /dev/sda1
mkdir: cannot create directory `/tmp/btrfs-dest': File exists
Create subvolume '/tmp/btrfs-dest/home'
Create a readonly snapshot of '/tmp/btrfs-source/home/@' in '/tmp/btrfs-source/home/@_ro/@'
ERROR: cannot snapshot '/tmp/btrfs-source/home/@' - Read-only file system
At subvol /tmp/btrfs-source/home/@_ro
At subvol @_ro
receiving subvol @_ro uuid=77b7abfb-655d-fd44-a1db-118ef7f95906, stransid=277
BTRFS_IOC_SEND returned 0
joining genl thread
BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=77b7abfb-655d-fd44-a1db-118ef7f95906, stransid=277
Create a snapshot of '/tmp/btrfs-dest/home/@_ro' in '/tmp/btrfs-dest/home/@'
Delete subvolume '/tmp/btrfs-dest/home/@_ro'
Delete subvolume '/tmp/btrfs-source/home/@_ro'
Create subvolume '/tmp/btrfs-dest/modules'
Create a readonly snapshot of '/tmp/btrfs-source/modules/@' in '/tmp/btrfs-source/modules/@_ro'
At subvol /tmp/btrfs-source/modules/@_ro
At subvol @_ro
receiving subvol @_ro uuid=588195d5-6299-fe4e-b6ff-a852d8d27d9d, stransid=160
BTRFS_IOC_SEND returned 0
BTRFS_IOC_SET_RECEIVED_SUBVOL uuid=588195d5-6299-fe4e-b6ff-a852d8d27d9d, stransid=160
joining genl thread
Create a snapshot of '/tmp/btrfs-dest/modules/@_ro' in '/tmp/btrfs-dest/modules/@'
Delete subvolume '/tmp/btrfs-dest/modules/@_ro'
Delete subvolume '/tmp/btrfs-source/modules/@_ro'
Create subvolume '/tmp/btrfs-dest/root'
Create a readonly snapshot of '/tmp/btrfs-source/root/@' in '/tmp/btrfs-source/root/@_ro/@'
ERROR: cannot snapshot '/tmp/btrfs-source/root/@' - Read-only file system
At subvol /tmp/btrfs-source/root/@_ro
At subvol @_ro
receiving subvol @_ro uuid=6d3a60d1-676a-734e-a4de-c65df30cccf6, stransid=73