3 Btrfs puts snapshots and subvolumes into the root directory of the FS. This
4 directory can only be changed by btrfsctl right now, and normal filesystem
5 operations do not work on it. The default subvolume is called 'default',
6 and you can create files and directories in mount_point/default
8 Btrfs uses the crypto manager interface in the kernel for file and
9 metadata checksums. You need to compile the kernel with:
12 CONFIG_CRYPTO_MANAGER=m
13 CONFIG_CRYPTO_CRC32C=m
15 cryptomanager and crc32c can be static as well. Once your kernel is
16 setup, typing make in the btrfs module sources will build against the
17 running kernel. When the build is complete:
23 The Btrfs utility programs require libuuid to build. This can be found
24 in the e2fsprogs sources, and is usually available as libuuid or
25 e2fsprogs-devel from various distros.
27 Building the utilities is just make ; make install. The programs go
28 into /usr/local/bin. The commands available are:
30 mkfs.btrfs: create a filesystem
32 btrfsctl: control program to create snapshots and subvolumes:
35 btrfsctl -s new_subvol_name /mnt
36 btrfsctl -s snapshot_of_default /mnt/default
37 btrfsctl -s snapshot_of_new_subvol /mnt/new_subvol_name
38 btrfsctl -s snapshot_of_a_snapshot /mnt/snapshot_of_new_subvol
40 default snapshot_of_a_snapshot snapshot_of_new_subvol
41 new_subvol_name snapshot_of_default
43 Snapshots and subvolumes cannot be deleted right now, but you can
44 rm -rf all the files and directories inside them.
46 btrfsck: do a limited check of the FS extent trees.</li>
48 debug-tree: print all of the FS metadata in text form. Example:
50 debug-tree /dev/sda2 >& big_output_file