mirror of
https://github.com/kdave/btrfs-progs
synced 2025-04-11 03:31:17 +00:00
74 lines
3.4 KiB
ReStructuredText
74 lines
3.4 KiB
ReStructuredText
Introduction
|
|
============
|
|
|
|
BTRFS is a modern copy on write (COW) filesystem for Linux aimed at
|
|
implementing advanced features while also focusing on fault tolerance, repair
|
|
and easy administration. Its main features and benefits are:
|
|
|
|
* Snapshots which do not make a full copy of the files
|
|
* Built-in volume management, support for software-based RAID 0, RAID 1, RAID 10 and others
|
|
* Self-healing - checksums for data and metadata, automatic detection of silent data corruptions
|
|
* Data compression
|
|
* Reflinks, fast and efficient file copies
|
|
|
|
Feature overview
|
|
----------------
|
|
|
|
* Extent based file storage
|
|
* 2\ :sup:`64` byte (16 EiB) :ref:`maximum file size<administration-limits>` (practical limit is 8 EiB due to Linux VFS)
|
|
* :doc:`Space-efficient packing of small files<Inline-files>`
|
|
* Space-efficient indexed directories
|
|
* :ref:`Dynamic inode allocation<administration-flexibility>`
|
|
* :doc:`Writable snapshots, read-only snapshots, subvolumes (separate internal filesystem roots)<Subvolumes>`
|
|
* :doc:`Checksums on data and metadata<Checksumming>` (crc32c, xxhash, sha256, blake2b)
|
|
* :doc:`Compression (ZLIB, LZO, ZSTD), heuristics<Compression>`
|
|
* :doc:`Integrated multiple device support<Volume-management>`:
|
|
|
|
* File Striping (like RAID0)
|
|
* File Mirroring (like RAID1 up to 4 copies)
|
|
* File Striping+Mirroring (like RAID10)
|
|
* Single and Dual Parity implementations (like RAID5/6, experimental, not production-ready)
|
|
|
|
* SSD/NVMe (flash storage) awareness, :doc:`TRIM/Discard<Trim>` for reporting free blocks for
|
|
reuse and optimizations (e.g. avoiding unnecessary seek optimizations,
|
|
sending writes in clusters.
|
|
* :doc:`Background scrub<Scrub>` process for finding and repairing errors of files with redundant copies
|
|
* :doc:`Online filesystem defragmentation<Defragmentation>`
|
|
* :doc:`Offline filesystem check<btrfs-check>`
|
|
* :doc:`In-place conversion<Convert>` of existing ext2/3/4 and reiserfs filesystems
|
|
* :doc:`Seeding device.<Seeding-device>` Create a (readonly) filesystem that
|
|
acts as a template to seed other Btrfs filesystems. The original filesystem
|
|
and devices are included as a readonly starting point for the new filesystem.
|
|
Using copy on write, all modifications are stored on different devices; the
|
|
original is unchanged.
|
|
* :doc:`Subvolume-aware quota<Qgroups>` support
|
|
* :doc:`Send/receive of subvolume changes<Send-receive>`, efficient
|
|
incremental filesystem mirroring and backup
|
|
* :doc:`Batch, or out-of-band deduplication<Deduplication>` (happens after writes, not during)
|
|
* :doc:`Swapfile support<Swapfile>`
|
|
* :doc:`Tree-checker<Tree-checker>`, post-read and pre-write metadata verification
|
|
* :doc:`Zoned mode support<Zoned-mode>` (SMR/ZBC/ZNS friendly allocation, emulated on non-zoned devices)
|
|
|
|
A more detailed list of features and compatibility is on the :doc:`status page <Status>`.
|
|
|
|
Quick start
|
|
-----------
|
|
|
|
For a really quick start you can simply create and mount the filesystem. Make
|
|
sure that the block device you'd like to use is suitable so you don't overwrite existing data.
|
|
|
|
.. code-block:: shell
|
|
|
|
# mkfs.btrfs /dev/sdx
|
|
# mount /dev/sdx /mnt/test
|
|
|
|
The default options should be acceptable for most users and sometimes can be
|
|
changed later. The example above is for a single device filesystem, creating a
|
|
*single* profile for data (no redundant copies of the blocks), and *DUP*
|
|
for metadata (each block is duplicated).
|
|
|
|
Read more about:
|
|
|
|
* creating a filesystem at :doc:`mkfs.btrfs`
|
|
* mount options at :doc:`Administration`
|