What is BorgBackup?¶
BorgBackup (short: Borg) is a deduplicating backup program. Optionally, it supports compression and authenticated encryption.
The main goal of Borg is to provide an efficient and secure way to backup data. The data deduplication technique used makes Borg suitable for daily backups since only changes are stored. The authenticated encryption technique makes it suitable for backups to not fully trusted targets.
See the installation manual or, if you have already
docs/installation.rst to get started with Borg.
- Space efficient storage
Deduplication based on content-defined chunking is used to reduce the number of bytes stored: each file is split into a number of variable length chunks and only chunks that have never been seen before are added to the repository.
A chunk is considered duplicate if its id_hash value is identical. A cryptographically strong hash or MAC function is used as id_hash, e.g. (hmac-)sha256.
To deduplicate, all the chunks in the same repository are considered, no matter whether they come from different machines, from previous backups, from the same backup or even from the same single file.
Compared to other deduplication approaches, this method does NOT depend on:
- file/directory names staying the same: So you can move your stuff around without killing the deduplication, even between machines sharing a repo.
- complete files or time stamps staying the same: If a big file changes a little, only a few new chunks need to be stored - this is great for VMs or raw disks.
- The absolute position of a data chunk inside a file: Stuff may get shifted and will still be found by the deduplication algorithm.
- performance critical code (chunking, compression, encryption) is implemented in C/Cython
- local caching of files/chunks index data
- quick detection of unmodified files
- Data encryption
- All data can be protected using 256-bit AES encryption, data integrity and authenticity is verified using HMAC-SHA256. Data is encrypted clientside.
- All data can be compressed by lz4 (super fast, low compression), zlib (medium speed and compression) or lzma (low speed, high compression).
- Off-site backups
- Borg can store data on any remote host accessible over SSH. If Borg is installed on the remote host, big performance gains can be achieved compared to using a network filesystem (sshfs, nfs, …).
- Backups mountable as filesystems
- Backup archives are mountable as userspace filesystems for easy interactive backup examination and restores (e.g. by using a regular file manager).
- Easy installation on multiple platforms
We offer single-file binaries that do not require installing anything - you can just run them on these platforms:
- Mac OS X
- OpenBSD and NetBSD (no xattrs/ACLs support or binaries yet)
- Cygwin (not supported, no binaries yet)
- Linux Subsystem of Windows 10 (not supported)
- Free and Open Source Software
- security and functionality can be audited independently
- licensed under the BSD (3-clause) license, see License for the complete license
Easy to use¶
Initialize a new backup repository and create a backup archive:
$ borg init /path/to/repo $ borg create /path/to/repo::Saturday1 ~/Documents
Now doing another backup, just to show off the great deduplication:
$ borg create -v --stats /path/to/repo::Saturday2 ~/Documents ----------------------------------------------------------------------------- Archive name: Saturday2 Archive fingerprint: 622b7c53c... Time (start): Sat, 2016-02-27 14:48:13 Time (end): Sat, 2016-02-27 14:48:14 Duration: 0.88 seconds Number of files: 163 ----------------------------------------------------------------------------- Original size Compressed size Deduplicated size This archive: 6.85 MB 6.85 MB 30.79 kB <-- ! All archives: 13.69 MB 13.71 MB 6.88 MB Unique chunks Total chunks Chunk index: 167 330 -----------------------------------------------------------------------------
For a graphical frontend refer to our complementary project BorgWeb.
Helping, Donations and Bounties¶
Your help is always welcome! Spread the word, give feedback, help with documentation, testing or development.
You can also give monetary support to the project, see there for details:
EXPECT THAT WE WILL BREAK COMPATIBILITY REPEATEDLY WHEN MAJOR RELEASE NUMBER CHANGES (like when going from 0.x.y to 1.0.0 or from 1.x.y to 2.0.0).
NOT RELEASED DEVELOPMENT VERSIONS HAVE UNKNOWN COMPATIBILITY PROPERTIES.
THIS IS SOFTWARE IN DEVELOPMENT, DECIDE YOURSELF WHETHER IT FITS YOUR NEEDS.
Security issues should be reported to the Security contact (or
docs/suppport.rst in the source distribution).
- Quick Start
- Frequently asked questions
- Can I backup VM disk images?
- Can I backup from multiple servers into a single repository?
- Can I copy or synchronize my repo to another location?
- Which file types, attributes, etc. are not preserved?
- Are there other known limitations?
- Why is my backup bigger than with attic? Why doesn’t Borg do compression by default?
- How can I specify the encryption passphrase programmatically?
- When backing up to remote encrypted repos, is encryption done locally?
- When backing up to remote servers, do I have to trust the remote server?
- How can I protect against a hacked backup client?
- How can I protect against a hacked backup server?
- How can I protect against theft, sabotage, lightning, fire, …?
- How do I report security issue with Borg?
- Why do I get “connection closed by remote” after a while?
- Why am I seeing idle borg serve processes on the repo server?
- The borg cache eats way too much disk space, what can I do?
- If a backup stops mid-way, does the already-backed-up data stay there?
- How can I backup huge file(s) over a unstable connection?
- Can I backup my root partition (/) with Borg?
- If it crashes with a UnicodeError, what can I do?
- I can’t extract non-ascii filenames by giving them on the commandline!?
- Can Borg add redundancy to the backup data to deal with hardware malfunction?
- Can Borg verify data integrity of a backup archive?
- I am seeing ‘A’ (added) status for a unchanged file!?
- It always chunks all my files, even unchanged ones!
- Is there a way to limit bandwidth with Borg?
- I am having troubles with some network/FUSE/special filesystem, why?
- Why does running ‘borg check –repair’ warn about data loss?
- Why isn’t there more progress / ETA information displayed?
- Why am I getting ‘Operation not permitted’ errors when backing up on sshfs?
- Requirements for the borg single-file binary, esp. (g)libc?
- Why was Borg forked from Attic?
- What are the differences between Attic and Borg?
- Important notes
- Version 1.0.13 (2019-02-15)
- Version 1.0.12 (2018-04-08)
- Version 1.0.11 (2017-07-21)
- Version 1.0.11rc1 (2017-06-27)
- Version 1.0.10 (2017-02-13)
- Version 1.0.10rc1 (2017-01-29)
- Version 1.0.9 (2016-12-20)
- Version 1.0.9rc1 (2016-11-27)
- Version 1.0.8 (2016-10-29)
- Version 1.0.8rc1 (2016-10-17)
- Version 1.0.7 (2016-08-19)
- Version 1.0.7rc2 (2016-08-13)
- Version 1.0.7rc1 (2016-08-05)
- Version 1.0.6 (2016-07-12)
- Version 1.0.6rc1 (2016-07-10)
- Version 1.0.5 (2016-07-07)
- Version 1.0.4 (2016-07-07)
- Version 1.0.3 (2016-05-20)
- Version 1.0.2 (2016-04-16)
- Version 1.0.1 (2016-04-08)
- Version 1.0.0 (2016-03-05)
- Version 1.0.0rc2 (2016-02-28)
- Version 1.0.0rc1 (2016-02-07)
- Version 0.30.0 (2016-01-23)
- Version 0.29.0 (2015-12-13)
- Version 0.28.2 (2015-11-15)
- Version 0.28.1 (2015-11-08)
- Version 0.28.0 (2015-11-08)
- Version 0.27.0 (2015-10-07)
- Version 0.26.1 (2015-09-28)
- Version 0.26.0 (2015-09-19)
- Version 0.25.0 (2015-08-29)
- Version 0.24.0 (2015-08-09)
- Version 0.23.0 (2015-06-11)
- Attic Changelog