path: root/Documentation/filesystems/btrfs.txt
diff options
Diffstat (limited to 'Documentation/filesystems/btrfs.txt')
1 files changed, 91 insertions, 0 deletions
diff --git a/Documentation/filesystems/btrfs.txt b/Documentation/filesystems/btrfs.txt
new file mode 100644
index 00000000..76713522
--- /dev/null
+++ b/Documentation/filesystems/btrfs.txt
@@ -0,0 +1,91 @@
+ =====
+Btrfs is a new copy on write filesystem for Linux aimed at
+implementing advanced features while focusing on fault tolerance,
+repair and easy administration. Initially developed by Oracle, Btrfs
+is licensed under the GPL and open for contribution from anyone.
+Linux has a wealth of filesystems to choose from, but we are facing a
+number of challenges with scaling to the large storage subsystems that
+are becoming common in today's data centers. Filesystems need to scale
+in their ability to address and manage large storage, and also in
+their ability to detect, repair and tolerate errors in the data stored
+on disk. Btrfs is under heavy development, and is not suitable for
+any uses other than benchmarking and review. The Btrfs disk format is
+not yet finalized.
+The main Btrfs features include:
+ * Extent based file storage (2^64 max file size)
+ * Space efficient packing of small files
+ * Space efficient indexed directories
+ * Dynamic inode allocation
+ * Writable snapshots
+ * Subvolumes (separate internal filesystem roots)
+ * Object level mirroring and striping
+ * Checksums on data and metadata (multiple algorithms available)
+ * Compression
+ * Integrated multiple device support, with several raid algorithms
+ * Online filesystem check (not yet implemented)
+ * Very fast offline filesystem check
+ * Efficient incremental backup and FS mirroring (not yet implemented)
+ * Online filesystem defragmentation
+ ============
+There is a Btrfs mailing list hosted on vger.kernel.org. You can
+find details on how to subscribe here:
+Mailing list archives are available from gmane:
+ ===
+Discussion of Btrfs also occurs on the #btrfs channel of the Freenode
+IRC network.
+ =========
+Userspace tools for creating and manipulating Btrfs file systems are
+available from the git repository at the following location:
+ http://git.kernel.org/?p=linux/kernel/git/mason/btrfs-progs.git
+ git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-progs.git
+These include the following tools:
+mkfs.btrfs: create a filesystem
+btrfsctl: control program to create snapshots and subvolumes:
+ mount /dev/sda2 /mnt
+ btrfsctl -s new_subvol_name /mnt
+ btrfsctl -s snapshot_of_default /mnt/default
+ btrfsctl -s snapshot_of_new_subvol /mnt/new_subvol_name
+ btrfsctl -s snapshot_of_a_snapshot /mnt/snapshot_of_new_subvol
+ ls /mnt
+ default snapshot_of_a_snapshot snapshot_of_new_subvol
+ new_subvol_name snapshot_of_default
+ Snapshots and subvolumes cannot be deleted right now, but you can
+ rm -rf all the files and directories inside them.
+btrfsck: do a limited check of the FS extent trees.
+btrfs-debug-tree: print all of the FS metadata in text form. Example:
+ btrfs-debug-tree /dev/sda2 >& big_output_file