btrfs-gui is a graphical user interface tool for inspecting and managing btrfs filesystems. It is capable of managing filesystems on the local machine, and filesystems on remote network-accessible machines. It requires root access to the machine to perform most of its tasks (but separates the root-access part from the GUI).
Development is in its early stages, and currently only disk usage information and a list of subvolumes is available.
If you only have python 3, you should be able to run the root-level helper after patching it with the 2to3 tool. When there's a "make install", this capability will be in-built.
btrfs-gui is currently available through its git repository:
$ git clone http://git.darksatanic.net/repo/btrfs-gui.git/
The repository can also be viewed through gitweb.
Note that the first time you download the git repository, you will need to run
make to generate the icons the GUI needs. This requires inkscape and imagemagick. If you do not have these, the makefile will download the icons from this site instead. The icon files are also shipped in the tarball distribution of btrfs-gui (see below).
You can also download tarballs of the latest releases and release candidates.
$ sudo python3 setup.py install
Run it with:
$ sudo btrfs-gui
The GUI will appear. (Note that although the GUI is started through sudo, the main part of the program immediately drops root privileges again: only a small helper app is actually run as root). Select "scan for filesystems" from the Filesystems menu, and a list of btrfs filesystems will be shown in the panel on the left-hand side. The underlying devices for each filesystem are also shown in the list. Double-click on a filesystem to select it.
The usage display shows, graphically, what space has been allocated and used. The topmost box by default shows only what has been allocated by the filesystem -- this may be only a fraction of the total space available. Where data is replicated (RAID-1, RAID-10 or DUP), only the size of the actual data is shown, not the total of all copies of it. (i.e. 10GiB of RAID-1 data is shown as 10GiB, not as 20GiB). The boxes underneath show the disk space used on each of the devices underlying the filesystem.
The striped sections show allocated but unused space; the black section at the beginning of each block is the system data.
The subvolume display lists all of the subvolumes of the filesystem. Subvolumes can be created from the "Subvolumes → New" menu, and deleted by selecting a subvolume in the list and using "Subvolumes → Delete", or right-clicking to bring up a context menu, and selecting "Delete".