Provided by: borgbackup_1.0.13-0ubuntu1.16.04.1_amd64 
NAME
borg - BorgBackup is a deduplicating backup program with optional compression and authenticated
encryption.
Borg consists of a number of commands. Each command accepts a number of arguments and options. The
following sections will describe each command in detail.
GENERAL
Positional Arguments and Options: Order matters
Borg only supports taking options (-v and --list in the example) to the left or right of all positional
arguments (repo::archive and path in the example), but not in between them:
borg extract -v --list repo::archive path # good and preferred
borg extract repo::archive path -v --list # also works
borg extract -v repo::archive path --list # works, but ugly
borg extract repo::archive -v --list path # BAD
This is due to a problem in the argparse module: http://bugs.python.org/issue15112
Repository URLs
Local filesystem (or locally mounted network filesystem):
/path/to/repo - filesystem path to repo directory, absolute path
path/to/repo - filesystem path to repo directory, relative path
Also, stuff like ~/path/to/repo or ~other/path/to/repo works (this is expanded by your shell).
Note: you may also prepend a file:// to a filesystem path to get URL style.
Remote repositories accessed via ssh user@host:
user@host:/path/to/repo - remote repo, absolute path
ssh://user@host:port/path/to/repo - same, alternative syntax, port can be given
Remote repositories with relative pathes can be given using this syntax:
user@host:path/to/repo - path relative to current directory
user@host:~/path/to/repo - path relative to user's home directory
user@host:~other/path/to/repo - path relative to other's home directory
Note: giving user@host:/./path/to/repo or user@host:/~/path/to/repo or user@host:/~other/path/to/repo is
also supported, but not required here.
Remote repositories with relative pathes, alternative syntax with port:
ssh://user@host:port/./path/to/repo - path relative to current directory
ssh://user@host:port/~/path/to/repo - path relative to user's home directory
ssh://user@host:port/~other/path/to/repo - path relative to other's home directory
If you frequently need the same repo URL, it is a good idea to set the BORG_REPO environment variable to
set a default for the repo URL:
export BORG_REPO='ssh://user@host:port/path/to/repo'
Then just leave away the repo URL if only a repo URL is needed and you want to use the default - it will
be read from BORG_REPO then.
Use :: syntax to give the repo URL when syntax requires giving a positional argument for the repo (e.g.
borg mount :: /mnt).
Repository / Archive Locations
Many commands want either a repository (just give the repo URL, see above) or an archive location, which
is a repo URL followed by ::archive_name.
Archive names must not contain the / (slash) character. For simplicity, maybe also avoid blanks or other
characters that have special meaning on the shell or in a filesystem (borg mount will use the archive
name as directory name).
If you have set BORG_REPO (see above) and an archive location is needed, use ::archive_name - the repo
URL part is then read from BORG_REPO.
Type of log output
The log level of the builtin logging configuration defaults to WARNING. This is because we want Borg to
be mostly silent and only output warnings, errors and critical messages.
Log levels: DEBUG < INFO < WARNING < ERROR < CRITICAL
Use --debug to set DEBUG log level - to get debug, info, warning, error and critical level output.
Use --info (or -v or --verbose) to set INFO log level - to get info, warning, error and critical level
output.
Use --warning (default) to set WARNING log level - to get warning, error and critical level output.
Use --error to set ERROR log level - to get error and critical level output.
Use --critical to set CRITICAL log level - to get critical level output.
While you can set misc. log levels, do not expect that every command will give different output on
different log levels - it's just a possibility.
WARNING:
Options --critical and --error are provided for completeness, their usage is not recommended as you
might miss important information.
WARNING:
While some options (like --stats or --list) will emit more informational messages, you have to use
INFO (or lower) log level to make them show up in log output. Use -v or a logging configuration.
Return codes
Borg can exit with the following return codes (rc):
0 = success (logged as INFO)
1 = warning (operation reached its normal end, but there were warnings -
you should check the log, logged as WARNING)
2 = error (like a fatal error, a local or remote exception, the operation
did not reach its normal end, logged as ERROR)
128+N = killed by signal N (e.g. 137 == kill -9)
If you use --show-rc, the return code is also logged at the indicated level as the last log entry.
Environment Variables
Borg uses some environment variables for automation:
General:
BORG_REPO
When set, use the value to give the default repository location. If a command needs an
archive parameter, you can abbreviate as ::archive. If a command needs a repository
parameter, you can either leave it away or abbreviate as ::, if a positional parameter is
required.
BORG_PASSPHRASE
When set, use the value to answer the passphrase question for encrypted repositories. It
is used when a passphrase is needed to access an encrypted repo as well as when a new
passphrase should be initially set when initializing an encrypted repo.
BORG_PASSCOMMAND
When set, use the standard output of the command (trailing newlines are stripped) to answer
the passphrase question for encrypted repositories. It is used when a passphrase is needed
to access an encrypted repo as well as when a new passphrase should be initially set when
initializing an encrypted repo. If BORG_PASSPHRASE is also set, it takes precedence.
BORG_PASSPHRASE_FD
When set, specifies a file descriptor to read a passphrase from. Programs starting borg may
choose to open an anonymous pipe and use it to pass a passphrase. This is safer than
passing via BORG_PASSPHRASE, because on some systems (e.g. Linux) environment can be
examined by other processes. If BORG_PASSPHRASE or BORG_PASSCOMMAND are also set, they
take precedence.
BORG_DISPLAY_PASSPHRASE
When set, use the value to answer the "display the passphrase for verification" question
when defining a new passphrase for encrypted repositories.
BORG_LOGGING_CONF
When set, use the given filename as INI-style logging configuration.
BORG_RSH
When set, use this command instead of ssh. This can be used to specify ssh options, such as
a custom identity file ssh -i /path/to/private/key. See man ssh for other options.
BORG_REMOTE_PATH
When set, use the given path as borg executable on the remote (defaults to "borg" if
unset). Using --remote-path PATH commandline option overrides the environment variable.
BORG_FILES_CACHE_TTL
When set to a numeric value, this determines the maximum "time to live" for the files cache
entries (default: 20). The files cache is used to quickly determine whether a file is
unchanged. The FAQ explains this more detailed in: always_chunking
TMPDIR where temporary files are stored (might need a lot of temporary space for some operations)
Some automatic answerers (if set, they automatically answer confirmation questions):
BORG_UNKNOWN_UNENCRYPTED_REPO_ACCESS_IS_OK=no (or =yes)
For "Warning: Attempting to access a previously unknown unencrypted repository"
BORG_RELOCATED_REPO_ACCESS_IS_OK=no (or =yes)
For "Warning: The repository at location ... was previously located at ..."
BORG_CHECK_I_KNOW_WHAT_I_AM_DOING=NO (or =YES)
For "Warning: 'check --repair' is an experimental feature that might result in data loss."
BORG_DELETE_I_KNOW_WHAT_I_AM_DOING=NO (or =YES)
For "You requested to completely DELETE the repository including all archives it contains:"
Note: answers are case sensitive. setting an invalid answer value might either give the default
answer or ask you interactively, depending on whether retries are allowed (they by default are
allowed). So please test your scripts interactively before making them a non-interactive script.
Directories:
BORG_KEYS_DIR
Default to '~/.config/borg/keys'. This directory contains keys for encrypted repositories.
BORG_SECURITY_DIR
Default to '~/.config/borg/security'. This directory is used by Borg to track various
pieces of security-related data.
BORG_CACHE_DIR
Default to '~/.cache/borg'. This directory contains the local cache and might need a lot of
space for dealing with big repositories).
Building:
BORG_OPENSSL_PREFIX
Adds given OpenSSL header file directory to the default locations (setup.py).
BORG_LZ4_PREFIX
Adds given LZ4 header file directory to the default locations (setup.py).
Please note:
• be very careful when using the "yes" sayers, the warnings with prompt exist for your / your data's
security/safety
• also be very careful when putting your passphrase into a script, make sure it has appropriate file
permissions (e.g. mode 600, root:root).
Resource Usage
Borg might use a lot of resources depending on the size of the data set it is dealing with.
If one uses Borg in a client/server way (with a ssh: repository), the resource usage occurs in part on
the client and in another part on the server.
If one uses Borg as a single process (with a filesystem repo), all the resource usage occurs in that one
process, so just add up client + server to get the approximate resource usage.
CPU client:
borg create: does chunking, hashing, compression, crypto (high CPU usage) chunks cache sync: quite
heavy on CPU, doing lots of hashtable operations. borg extract: crypto, decompression (medium to
high CPU usage) borg check: similar to extract, but depends on options given. borg prune / borg
delete archive: low to medium CPU usage borg delete repo: done on the server It won't go beyond
100% of 1 core as the code is currently single-threaded. Especially higher zlib and lzma
compression levels use significant amounts of CPU cycles. Crypto might be cheap on the CPU (if
hardware accelerated) or expensive (if not).
CPU server:
It usually doesn't need much CPU, it just deals with the key/value store (repository) and uses the
repository index for that.
borg check: the repository check computes the checksums of all chunks (medium CPU usage) borg
delete repo: low CPU usage
CPU (only for client/server operation):
When using borg in a client/server way with a ssh:-type repo, the ssh processes used for the
transport layer will need some CPU on the client and on the server due to the crypto they are
doing - esp. if you are pumping big amounts of data.
Memory (RAM) client:
The chunks index and the files index are read into memory for performance reasons. Might need big
amounts of memory (see below). Compression, esp. lzma compression with high levels might need
substantial amounts of memory.
Memory (RAM) server:
The server process will load the repository index into memory. Might need considerable amounts of
memory, but less than on the client (see below).
Chunks index (client only):
Proportional to the amount of data chunks in your repo. Lots of chunks in your repo imply a big
chunks index. It is possible to tweak the chunker params (see create options).
Files index (client only):
Proportional to the amount of files in your last backups. Can be switched off (see create
options), but next backup might be much slower if you do. The speed benefit of using the files
cache is proportional to file size.
Repository index (server only):
Proportional to the amount of data chunks in your repo. Lots of chunks in your repo imply a big
repository index. It is possible to tweak the chunker params (see create options) to influence
the amount of chunks being created.
Temporary files (client):
Reading data and metadata from a FUSE mounted repository will consume up to the size of all
deduplicated, small chunks in the repository. Big chunks won't be locally cached.
Temporary files (server):
None.
Cache files (client only):
Contains the chunks index and files index (plus a collection of single- archive chunk indexes
which might need huge amounts of disk space, depending on archive count and size - see FAQ about
how to reduce).
Network (only for client/server operation):
If your repository is remote, all deduplicated (and optionally compressed/ encrypted) data of
course has to go over the connection (ssh: repo url). If you use a locally mounted network
filesystem, additionally some copy operations used for transaction support also go over the
connection. If you backup multiple sources to one target repository, additional traffic happens
for cache resynchronization.
In case you are interested in more details (like formulas), please see internals.
Units
To display quantities, Borg takes care of respecting the usual conventions of scale. Disk sizes are
displayed in decimal, using powers of ten (so kB means 1000 bytes). For memory usage, binary prefixes are
used, and are indicated using the IEC binary prefixes, using powers of two (so KiB means 1024 bytes).
Date and Time
We format date and time conforming to ISO-8601, that is: YYYY-MM-DD and HH:MM:SS (24h clock).
For more information about that, see: https://xkcd.com/1179/
Unless otherwise noted, we display local date and time. Internally, we store and process date and time
as UTC.
BORG INIT
usage: borg init [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [-e {none,keyfile,repokey}] [-a]
[REPOSITORY]
Initialize an empty repository
positional arguments:
REPOSITORY repository to create
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
-e {none,keyfile,repokey}, --encryption {none,keyfile,repokey}
select encryption key mode (default: "repokey")
-a, --append-only create an append-only mode repository
Description
This command initializes an empty repository. A repository is a filesystem directory containing the
deduplicated data from zero or more archives. Encryption can be enabled at repository init time.
Examples
# Local repository (default is to use encryption in repokey mode)
$ borg init /path/to/repo
# Local repository (no encryption)
$ borg init --encryption=none /path/to/repo
# Remote repository (accesses a remote borg via ssh)
$ borg init user@hostname:backup
# Remote repository (store the key your home dir)
$ borg init --encryption=keyfile user@hostname:backup
Important notes about encryption:
It is not recommended to disable encryption. Repository encryption protects you e.g. against the case
that an attacker has access to your backup repository.
But be careful with the key / the passphrase:
If you want "passphrase-only" security, use the repokey mode. The key will be stored inside the
repository (in its "config" file). In above mentioned attack scenario, the attacker will have the key
(but not the passphrase).
If you want "passphrase and having-the-key" security, use the keyfile mode. The key will be stored in
your home directory (in .config/borg/keys). In the attack scenario, the attacker who has just access to
your repo won't have the key (and also not the passphrase).
Make a backup copy of the key file (keyfile mode) or repo config file (repokey mode) and keep it at a
safe place, so you still have the key in case it gets corrupted or lost. Also keep the passphrase at a
safe place. The backup that is encrypted with that key won't help you with that, of course.
Make sure you use a good passphrase. Not too short, not too simple. The real encryption / decryption key
is encrypted with / locked by your passphrase. If an attacker gets your key, he can't unlock and use it
without knowing the passphrase.
Be careful with special or non-ascii characters in your passphrase:
• Borg processes the passphrase as unicode (and encodes it as utf-8), so it does not have problems
dealing with even the strangest characters.
• BUT: that does not necessarily apply to your OS / VM / keyboard configuration.
So better use a long passphrase made from simple ascii chars than one that includes non-ascii stuff or
characters that are hard/impossible to enter on a different keyboard layout.
You can change your passphrase for existing repos at any time, it won't affect the encryption/decryption
key or other secrets.
BORG CREATE
usage: borg create [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [-s] [-p] [--list]
[--filter STATUSCHARS] [-e PATTERN]
[--exclude-from EXCLUDEFILE] [--exclude-caches]
[--exclude-if-present FILENAME] [--keep-tag-files]
[-c SECONDS] [-x] [--numeric-owner] [--noatime] [--noctime]
[--timestamp yyyy-mm-ddThh:mm:ss]
[--chunker-params CHUNK_MIN_EXP,CHUNK_MAX_EXP,HASH_MASK_BITS,HASH_WINDOW_SIZE]
[--ignore-inode] [-C COMPRESSION] [--read-special] [-n]
ARCHIVE PATH [PATH ...]
Create new archive
positional arguments:
ARCHIVE name of archive to create (must be also a valid
directory name)
PATH paths to archive
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
-s, --stats print statistics for the created archive. Requires
-v/--verbose.
-p, --progress show progress display while creating the archive,
showing Original, Compressed and Deduplicated sizes,
followed by the Number of files seen and the path
being processed, default: False
--list output verbose list of items (files, dirs, ...).
Requires -v/--verbose.
--filter STATUSCHARS only display items with the given status characters
-e PATTERN, --exclude PATTERN
exclude paths matching PATTERN
--exclude-from EXCLUDEFILE
read exclude patterns from EXCLUDEFILE, one per line
--exclude-caches exclude directories that contain a CACHEDIR.TAG file
(http://www.brynosaurus.com/cachedir/spec.html)
--exclude-if-present FILENAME
exclude directories that contain the specified file
--keep-tag-files keep tag files of excluded caches/directories
-c SECONDS, --checkpoint-interval SECONDS
write checkpoint every SECONDS seconds (Default: 1800)
-x, --one-file-system
stay in same file system
--numeric-owner only store numeric user and group identifiers
--noatime do not store atime into archive
--noctime do not store ctime into archive
--timestamp yyyy-mm-ddThh:mm:ss
manually specify the archive creation date/time (UTC).
alternatively, give a reference file/directory.
--chunker-params CHUNK_MIN_EXP,CHUNK_MAX_EXP,HASH_MASK_BITS,HASH_WINDOW_SIZE
specify the chunker parameters. default: 19,23,21,4095
--ignore-inode ignore inode data in the file metadata cache used to
detect unchanged files.
-C COMPRESSION, --compression COMPRESSION
select compression algorithm (and level): none == no
compression (default), lz4 == lz4, zlib == zlib
(default level 6), zlib,0 .. zlib,9 == zlib (with
level 0..9), lzma == lzma (default level 6), lzma,0 ..
lzma,9 == lzma (with level 0..9).
--read-special open and read block and char device files as well as
FIFOs as if they were regular files. Also follows
symlinks pointing to these kinds of files.
-n, --dry-run do not create a backup archive
Description
This command creates a backup archive containing all files found while recursively traversing all paths
specified. Paths are added to the archive as they are given, that means if relative paths are desired,
the command has to be run from the correct directory.
When giving '-' as path, borg will read data from standard input and create a file 'stdin' in the created
archive from that data.
The archive will consume almost no disk space for files or parts of files that have already been stored
in other archives.
The archive name needs to be unique. It must not end in '.checkpoint' or '.checkpoint.N' (with N being a
number), because these names are used for checkpoints and treated in special ways.
In the archive name, you may use the following placeholders: {now}, {utcnow}, {fqdn}, {hostname}, {user}
and some others.
To speed up pulling backups over sshfs and similar network file systems which do not provide correct
inode information the --ignore-inode flag can be used. This potentially decreases reliability of change
detection, while avoiding always reading all files on these file systems.
The mount points of filesystems or filesystem snapshots should be the same for every creation of a new
archive to ensure fast operation. This is because the file cache that is used to determine changed files
quickly uses absolute filenames. If this is not possible, consider creating a bind mount to a stable
location.
See the output of the "borg help patterns" command for more help on exclude patterns. See the output of
the "borg help placeholders" command for more help on placeholders.
Borg respects the nodump flag. Files flagged nodump will be marked as excluded (x) in --list output.
Examples
# Backup ~/Documents into an archive named "my-documents"
$ borg create /path/to/repo::my-documents ~/Documents
# same, but verbosely list all files as we process them
$ borg create -v --list /path/to/repo::my-documents ~/Documents
# Backup ~/Documents and ~/src but exclude pyc files
$ borg create /path/to/repo::my-files \
~/Documents \
~/src \
--exclude '*.pyc'
# Backup home directories excluding image thumbnails (i.e. only
# /home/*/.thumbnails is excluded, not /home/*/*/.thumbnails)
$ borg create /path/to/repo::my-files /home \
--exclude 're:^/home/[^/]+/\.thumbnails/'
# Do the same using a shell-style pattern
$ borg create /path/to/repo::my-files /home \
--exclude 'sh:/home/*/.thumbnails'
# Backup the root filesystem into an archive named "root-YYYY-MM-DD"
# use zlib compression (good, but slow) - default is no compression
$ borg create -C zlib,6 --one-file-system /path/to/repo::root-{now:%Y-%m-%d} /
# Make a big effort in fine granular deduplication (big chunk management
# overhead, needs a lot of RAM and disk space, see formula in internals
# docs - same parameters as borg < 1.0 or attic):
$ borg create --chunker-params 10,23,16,4095 /path/to/repo::small /smallstuff
# Backup a raw device (must not be active/in use/mounted at that time)
$ dd if=/dev/sdx bs=10M | borg create /path/to/repo::my-sdx -
# No compression (default)
$ borg create /path/to/repo::arch ~
# Super fast, low compression
$ borg create --compression lz4 /path/to/repo::arch ~
# Less fast, higher compression (N = 0..9)
$ borg create --compression zlib,N /path/to/repo::arch ~
# Even slower, even higher compression (N = 0..9)
$ borg create --compression lzma,N /path/to/repo::arch ~
# Use short hostname, user name and current time in archive name
$ borg create /path/to/repo::{hostname}-{user}-{now} ~
# Similar, use the same datetime format as borg 1.1 will have as default
$ borg create /path/to/repo::{hostname}-{user}-{now:%Y-%m-%dT%H:%M:%S} ~
# As above, but add nanoseconds
$ borg create /path/to/repo::{hostname}-{user}-{now:%Y-%m-%dT%H:%M:%S.%f} ~
# Backing up relative paths by moving into the correct directory first
$ cd /home/user/Documents
# The root directory of the archive will be "projectA"
$ borg create /path/to/repo::daily-projectA-{now:%Y-%m-%d} projectA
Notes
• the --exclude patterns are not like tar. In tar --exclude .bundler/gems will exclude foo/.bundler/gems.
In borg it will not, you need to use --exclude '*/.bundler/gems' to get the same effect. See borg help
patterns for more information.
BORG EXTRACT
usage: borg extract [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [--list] [-n] [-e PATTERN]
[--exclude-from EXCLUDEFILE] [--numeric-owner]
[--strip-components NUMBER] [--stdout] [--sparse]
ARCHIVE [PATH [PATH ...]]
Extract archive contents
positional arguments:
ARCHIVE archive to extract
PATH paths to extract; patterns are supported
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
--list output verbose list of items (files, dirs, ...).
Requires -v/--verbose.
-n, --dry-run do not actually change any files
-e PATTERN, --exclude PATTERN
exclude paths matching PATTERN
--exclude-from EXCLUDEFILE
read exclude patterns from EXCLUDEFILE, one per line
--numeric-owner only obey numeric user and group identifiers
--strip-components NUMBER
Remove the specified number of leading path elements.
Pathnames with fewer elements will be silently
skipped.
--stdout write all extracted data to stdout
--sparse create holes in output sparse file from all-zero
chunks
Description
This command extracts the contents of an archive. By default the entire archive is extracted but a subset
of files and directories can be selected by passing a list of PATHs as arguments. The file selection can
further be restricted by using the --exclude option.
See the output of the "borg help patterns" command for more help on exclude patterns.
Examples
# Extract entire archive
$ borg extract /path/to/repo::my-files
# Extract entire archive and list files while processing
$ borg extract -v --list /path/to/repo::my-files
# Extract the "src" directory
$ borg extract /path/to/repo::my-files home/USERNAME/src
# Extract the "src" directory but exclude object files
$ borg extract /path/to/repo::my-files home/USERNAME/src --exclude '*.o'
# Restore a raw device (must not be active/in use/mounted at that time)
$ borg extract --stdout /path/to/repo::my-sdx | dd of=/dev/sdx bs=10M
Note: currently, extract always writes into the current working directory ("."),
so make sure you cd to the right place before calling borg extract.
BORG CHECK
usage: borg check [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [--repository-only] [--archives-only]
[--repair] [--save-space] [--last N] [-P PREFIX]
[REPOSITORY_OR_ARCHIVE]
Check repository consistency
positional arguments:
REPOSITORY_OR_ARCHIVE
repository or archive to check consistency of
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
--repository-only only perform repository checks
--archives-only only perform archives checks
--repair attempt to repair any inconsistencies found
--save-space work slower, but using less space
--last N only check last N archives (Default: all)
-P PREFIX, --prefix PREFIX
only consider archive names starting with this prefix
Description
The check command verifies the consistency of a repository and the corresponding archives.
First, the underlying repository data files are checked:
• For all segments the segment magic (header) is checked
• For all objects stored in the segments, all metadata (e.g. crc and size) and all data is read. The read
data is checked by size and CRC. Bit rot and other types of accidental damage can be detected this way.
• If we are in repair mode and a integrity error is detected for a segment, we try to recover as many
objects from the segment as possible.
• In repair mode, it makes sure that the index is consistent with the data stored in the segments.
• If you use a remote repo server via ssh:, the repo check is executed on the repo server without causing
significant network traffic.
• The repository check can be skipped using the --archives-only option.
Second, the consistency and correctness of the archive metadata is verified:
• Is the repo manifest present? If not, it is rebuilt from archive metadata chunks (this requires reading
and decrypting of all metadata and data).
• Check if archive metadata chunk is present. if not, remove archive from manifest.
• For all files (items) in the archive, for all chunks referenced by these files, check if chunk is
present. If a chunk is not present and we are in repair mode, replace it with a same-size replacement
chunk of zeros. If a previously lost chunk reappears (e.g. via a later backup) and we are in repair
mode, the all-zero replacement chunk will be replaced by the correct chunk. This requires reading of
archive and file metadata, but not data.
• If we are in repair mode and we checked all the archives: delete orphaned chunks from the repo.
• if you use a remote repo server via ssh:, the archive check is executed on the client machine (because
if encryption is enabled, the checks will require decryption and this is always done client-side,
because key access will be required).
• The archive checks can be time consuming, they can be skipped using the --repository-only option.
BORG RENAME
usage: borg rename [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH]
ARCHIVE NEWNAME
Rename an existing archive
positional arguments:
ARCHIVE archive to rename
NEWNAME the new archive name to use
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
Description
This command renames an archive in the repository.
Examples
$ borg create /path/to/repo::archivename ~
$ borg list /path/to/repo
archivename Mon, 2016-02-15 19:50:19
$ borg rename /path/to/repo::archivename newname
$ borg list /path/to/repo
newname Mon, 2016-02-15 19:50:19
BORG LIST
usage: borg list [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [--short] [--list-format LISTFORMAT]
[-P PREFIX]
[REPOSITORY_OR_ARCHIVE]
List archive or repository contents
positional arguments:
REPOSITORY_OR_ARCHIVE
repository/archive to list contents of
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
--short only print file/directory names, nothing else
--list-format LISTFORMAT
specify format for archive file listing (default:
"{mode} {user:6} {group:6} {size:8d} {isomtime}
{path}{extra}{NEWLINE}") Special "{formatkeys}" exists
to list available keys
-P PREFIX, --prefix PREFIX
only consider archive names starting with this prefix
Description
This command lists the contents of a repository or an archive.
Examples
$ borg list /path/to/repo
Monday Mon, 2016-02-15 19:15:11
repo Mon, 2016-02-15 19:26:54
root-2016-02-15 Mon, 2016-02-15 19:36:29
newname Mon, 2016-02-15 19:50:19
...
$ borg list /path/to/repo::root-2016-02-15
drwxr-xr-x root root 0 Mon, 2016-02-15 17:44:27 .
drwxrwxr-x root root 0 Mon, 2016-02-15 19:04:49 bin
-rwxr-xr-x root root 1029624 Thu, 2014-11-13 00:08:51 bin/bash
lrwxrwxrwx root root 0 Fri, 2015-03-27 20:24:26 bin/bzcmp -> bzdiff
-rwxr-xr-x root root 2140 Fri, 2015-03-27 20:24:22 bin/bzdiff
...
$ borg list /path/to/repo::archiveA --list-format="{mode} {user:6} {group:6} {size:8d} {isomtime} {path}{extra}{NEWLINE}"
drwxrwxr-x user user 0 Sun, 2015-02-01 11:00:00 .
drwxrwxr-x user user 0 Sun, 2015-02-01 11:00:00 code
drwxrwxr-x user user 0 Sun, 2015-02-01 11:00:00 code/myproject
-rw-rw-r-- user user 1416192 Sun, 2015-02-01 11:00:00 code/myproject/file.ext
...
# see what is changed between archives, based on file modification time, size and file path
$ borg list /path/to/repo::archiveA --list-format="{mtime:%s}{TAB}{size}{TAB}{path}{LF}" |sort -n > /tmp/list.archiveA
$ borg list /path/to/repo::archiveB --list-format="{mtime:%s}{TAB}{size}{TAB}{path}{LF}" |sort -n > /tmp/list.archiveB
$ diff -y /tmp/list.archiveA /tmp/list.archiveB
1422781200 0 . 1422781200 0 .
1422781200 0 code 1422781200 0 code
1422781200 0 code/myproject 1422781200 0 code/myproject
1422781200 1416192 code/myproject/file.ext | 1454664653 1416192 code/myproject/file.ext
...
BORG DELETE
usage: borg delete [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [-p] [-s] [-c] [--force]
[--save-space]
[TARGET]
Delete an existing repository or archive
positional arguments:
TARGET archive or repository to delete
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
-p, --progress show progress display while deleting a single archive
-s, --stats print statistics for the deleted archive. Requires
-v/--verbose.
-c, --cache-only delete only the local cache for the given repository
--force force deletion of corrupted archives, use --force
--force in case --force does not work.
--save-space work slower, but using less space
Description
This command deletes an archive from the repository or the complete repository. Disk space is reclaimed
accordingly. If you delete the complete repository, the local cache for it (if any) is also deleted.
Examples
# delete a single backup archive:
$ borg delete /path/to/repo::Monday
# delete the whole repository and the related local cache:
$ borg delete /path/to/repo
You requested to completely DELETE the repository *including* all archives it contains:
repo Mon, 2016-02-15 19:26:54
root-2016-02-15 Mon, 2016-02-15 19:36:29
newname Mon, 2016-02-15 19:50:19
Type 'YES' if you understand this and want to continue: YES
BORG PRUNE
usage: borg prune [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [-n] [--force] [-s] [--list]
[--keep-within INTERVAL] [-H HOURLY] [-d DAILY] [-w WEEKLY]
[-m MONTHLY] [-y YEARLY] [-P PREFIX] [--save-space]
[REPOSITORY]
Prune repository archives according to specified rules
positional arguments:
REPOSITORY repository to prune
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
-n, --dry-run do not change repository
--force force pruning of corrupted archives
-s, --stats print statistics for the deleted archive. Requires
-v/--verbose.
--list output verbose list of archives it keeps/prunes.
Requires -v/--verbose.
--keep-within INTERVAL
keep all archives within this time interval
-H HOURLY, --keep-hourly HOURLY
number of hourly archives to keep
-d DAILY, --keep-daily DAILY
number of daily archives to keep
-w WEEKLY, --keep-weekly WEEKLY
number of weekly archives to keep
-m MONTHLY, --keep-monthly MONTHLY
number of monthly archives to keep
-y YEARLY, --keep-yearly YEARLY
number of yearly archives to keep
-P PREFIX, --prefix PREFIX
only consider archive names starting with this prefix
--save-space work slower, but using less space
Description
The prune command prunes a repository by deleting all archives not matching any of the specified
retention options. This command is normally used by automated backup scripts wanting to keep a certain
number of historic backups.
As an example, "-d 7" means to keep the latest backup on each day, up to 7 most recent days with backups
(days without backups do not count). The rules are applied from hourly to yearly, and backups selected
by previous rules do not count towards those of later rules. The time that each backup starts is used for
pruning purposes. Dates and times are interpreted in the local timezone, and weeks go from Monday to
Sunday. Specifying a negative number of archives to keep means that there is no limit.
The "--keep-within" option takes an argument of the form "<int><char>", where char is "H", "d", "w", "m",
"y". For example, "--keep-within 2d" means to keep all archives that were created within the past 48
hours. "1m" is taken to mean "31d". The archives kept with this option do not count towards the totals
specified by any other options.
If a prefix is set with -P, then only archives that start with the prefix are considered for deletion and
only those archives count towards the totals specified by the rules. Otherwise, all archives in the
repository are candidates for deletion! There is no automatic distinction between archives representing
different contents. These need to be distinguished by specifying matching prefixes.
Examples
Be careful, prune is a potentially dangerous command, it will remove backup archives.
The default of prune is to apply to all archives in the repository unless you restrict its operation to a
subset of the archives using --prefix. When using --prefix, be careful to choose a good prefix - e.g. do
not use a prefix "foo" if you do not also want to match "foobar".
It is strongly recommended to always run prune -v --list --dry-run ... first so you will see what it
would do without it actually doing anything.
There is also a visualized prune example in docs/misc/prune-example.txt.
# Keep 7 end of day and 4 additional end of week archives.
# Do a dry-run without actually deleting anything.
$ borg prune -v --list --dry-run --keep-daily=7 --keep-weekly=4 /path/to/repo
# Same as above but only apply to archive names starting with the hostname
# of the machine followed by a "-" character:
$ borg prune -v --list --keep-daily=7 --keep-weekly=4 --prefix='{hostname}-' /path/to/repo
# Keep 7 end of day, 4 additional end of week archives,
# and an end of month archive for every month:
$ borg prune -v --list --keep-daily=7 --keep-weekly=4 --keep-monthly=-1 /path/to/repo
# Keep all backups in the last 10 days, 4 additional end of week archives,
# and an end of month archive for every month:
$ borg prune -v --list --keep-within=10d --keep-weekly=4 --keep-monthly=-1 /path/to/repo
BORG INFO
usage: borg info [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH]
ARCHIVE
Show archive details such as disk space used
positional arguments:
ARCHIVE archive to display information about
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
Description
This command displays some detailed information about the specified archive.
Please note that the deduplicated sizes of the individual archives do not add up to the deduplicated size
of the repository ("all archives"), because the two are meaning different things:
This archive / deduplicated size = amount of data stored ONLY for this archive
= unique chunks of this archive.
All archives / deduplicated size = amount of data stored in the repo
= all chunks in the repository.
Examples
$ borg info /path/to/repo::root-2016-02-15
Name: root-2016-02-15
Fingerprint: 57c827621f21b000a8d363c1e163cc55983822b3afff3a96df595077a660be50
Hostname: myhostname
Username: root
Time (start): Mon, 2016-02-15 19:36:29
Time (end): Mon, 2016-02-15 19:39:26
Command line: /usr/local/bin/borg create -v --list -C zlib,6 /path/to/repo::root-2016-02-15 / --one-file-system
Number of files: 38100
Original size Compressed size Deduplicated size
This archive: 1.33 GB 613.25 MB 571.64 MB
All archives: 1.63 GB 853.66 MB 584.12 MB
Unique chunks Total chunks
Chunk index: 36858 48844
BORG MOUNT
usage: borg mount [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [-f] [-o OPTIONS]
REPOSITORY_OR_ARCHIVE MOUNTPOINT
Mount archive or an entire repository as a FUSE filesystem
positional arguments:
REPOSITORY_OR_ARCHIVE
repository/archive to mount
MOUNTPOINT where to mount filesystem
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
-f, --foreground stay in foreground, do not daemonize
-o OPTIONS Extra mount options
Description
This command mounts an archive as a FUSE filesystem. This can be useful for browsing an archive or
restoring individual files. Unless the --foreground option is given the command will run in the
background until the filesystem is umounted.
The BORG_MOUNT_DATA_CACHE_ENTRIES environment variable is meant for advanced users to tweak the
performance. It sets the number of cached data chunks; additional memory usage can be up to ~8 MiB times
this number. The default is the number of CPU cores.
For FUSE configuration and mount options, see the mount.fuse(8) manual page.
Additional mount options supported by borg: - allow_damaged_files: by default damaged files (where
missing chunks were
replaced with runs of zeros by borg check --repair) are not readable and return EIO (I/O error). Set
this option to read such files.
• ignore_permissions: for security reasons the "default_permissions" mount option is internally enforced
by borg. "ignore_permissions" can be given to not enforce "default_permissions".
When the daemonized process receives a signal or crashes, it does not unmount. Unmounting in these cases
could cause an active rsync or similar process to unintentionally delete data.
When running in the foreground ^C/SIGINT unmounts cleanly, but other signals or crashes do not.
BORG UMOUNT
usage: borg umount [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH]
MOUNTPOINT
un-mount the FUSE filesystem
positional arguments:
MOUNTPOINT mountpoint of the filesystem to umount
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
Description
This command un-mounts a FUSE filesystem that was mounted with borg mount.
This is a convenience wrapper that just calls the platform-specific shell command - usually this is
either umount or fusermount -u.
Examples
$ borg mount /path/to/repo::root-2016-02-15 /tmp/mymountpoint
$ ls /tmp/mymountpoint
bin boot etc home lib lib64 lost+found media mnt opt root sbin srv tmp usr var
$ borg umount /tmp/mymountpoint
BORG KEY EXPORT
usage: borg key export [-h] [--critical] [--error] [--warning] [--info]
[--debug] [--lock-wait N] [--show-rc]
[--no-files-cache] [--umask M] [--remote-path PATH]
[--paper] [--qr-html]
[REPOSITORY] [PATH]
Export the repository key for backup
positional arguments:
REPOSITORY
PATH where to store the backup
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
--paper Create an export suitable for printing and later type-
in
--qr-html Create an html file suitable for printing and later
type-in or qr scan
Description
If repository encryption is used, the repository is inaccessible without the key. This command allows to
backup this essential key. Note that the backup produced does not include the passphrase itself (i.e.
the exported key stays encrypted). In order to regain access to a repository, one needs both the exported
key and the original passphrase.
There are two backup formats. The normal backup format is suitable for digital storage as a file. The
--paper backup format is optimized for printing and typing in while importing, with per line checks to
reduce problems with manual input.
For repositories using keyfile encryption the key is saved locally on the system that is capable of doing
backups. To guard against loss of this key, the key needs to be backed up independently of the main data
backup.
For repositories using the repokey encryption the key is saved in the repository in the config file. A
backup is thus not strictly needed, but guards against the repository becoming inaccessible if the file
is damaged for some reason.
BORG KEY IMPORT
usage: borg key import [-h] [--critical] [--error] [--warning] [--info]
[--debug] [--lock-wait N] [--show-rc]
[--no-files-cache] [--umask M] [--remote-path PATH]
[--paper]
[REPOSITORY] [PATH]
Import the repository key from backup
positional arguments:
REPOSITORY
PATH path to the backup
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
--paper interactively import from a backup done with --paper
Description
This command allows to restore a key previously backed up with the export command.
If the --paper option is given, the import will be an interactive process in which each line is checked
for plausibility before proceeding to the next line. For this format PATH must not be given.
BORG CHANGE-PASSPHRASE
usage: borg change-passphrase [-h] [--critical] [--error] [--warning] [--info]
[--debug] [--lock-wait N] [--show-rc]
[--no-files-cache] [--umask M]
[--remote-path PATH]
[REPOSITORY]
Change repository key file passphrase
positional arguments:
REPOSITORY
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
Description
The key files used for repository encryption are optionally passphrase protected. This command can be
used to change this passphrase.
Please note that this command only changes the passphrase, but not any secret protected by it (like e.g.
encryption/MAC keys or chunker seed). Thus, changing the passphrase after passphrase and borg key got
compromised does not protect future (nor past) backups to the same repository.
Examples
# Create a key file protected repository
$ borg init --encryption=keyfile -v /path/to/repo
Initializing repository at "/path/to/repo"
Enter new passphrase:
Enter same passphrase again:
Remember your passphrase. Your data will be inaccessible without it.
Key in "/root/.config/borg/keys/mnt_backup" created.
Keep this key safe. Your data will be inaccessible without it.
Synchronizing chunks cache...
Archives: 0, w/ cached Idx: 0, w/ outdated Idx: 0, w/o cached Idx: 0.
Done.
# Change key file passphrase
$ borg change-passphrase -v /path/to/repo
Enter passphrase for key /root/.config/borg/keys/mnt_backup:
Enter new passphrase:
Enter same passphrase again:
Remember your passphrase. Your data will be inaccessible without it.
Key updated
BORG SERVE
usage: borg serve [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [--restrict-to-path PATH]
[--append-only]
Start in server mode. This command is usually not used manually.
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
--restrict-to-path PATH
restrict repository access to PATH. Can be specified
multiple times to allow the client access to several
directories. Access to all sub-directories is granted
implicitly; PATH doesn't need to directly point to a
repository.
--append-only only allow appending to repository segment files
Description
This command starts a repository server process. This command is usually not used manually.
Examples
borg serve has special support for ssh forced commands (see authorized_keys example below): it will
detect that you use such a forced command and extract the value of the --restrict-to-path option(s). It
will then parse the original command that came from the client, makes sure that it is also borg serve and
enforce path restriction(s) as given by the forced command. That way, other options given by the client
(like --info or --umask) are preserved (and are not fixed by the forced command).
# Allow an SSH keypair to only run borg, and only have access to /path/to/repo.
# Use key options to disable unneeded and potentially dangerous SSH functionality.
# This will help to secure an automated remote backup system.
$ cat ~/.ssh/authorized_keys
command="borg serve --restrict-to-path /path/to/repo",no-pty,no-agent-forwarding,no-port-forwarding,no-X11-forwarding,no-user-rc ssh-rsa AAAAB3[...]
BORG UPGRADE
usage: borg upgrade [-h] [--critical] [--error] [--warning] [--info] [--debug]
[--lock-wait N] [--show-rc] [--no-files-cache] [--umask M]
[--remote-path PATH] [-p] [-n] [-i] [--force] [--tam]
[--disable-tam]
[REPOSITORY]
upgrade a repository from a previous version
positional arguments:
REPOSITORY path to the repository to be upgraded
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
-p, --progress show progress display while upgrading the repository
-n, --dry-run do not change repository
-i, --inplace rewrite repository in place, with no chance of going
back to older versions of the repository.
--force Force upgrade
--tam Enable manifest authentication (in key and cache)
(Borg 1.0.9 and later)
--disable-tam Disable manifest authentication (in key and cache)
Description
Upgrade an existing, local Borg repository.
When you do not need borg upgrade
Not every change requires that you run borg upgrade.
You do not need to run it when:
• moving your repository to a different place
• upgrading to another point release (like 1.0.x to 1.0.y), except when noted otherwise in the changelog
• upgrading from 1.0.x to 1.1.x, except when noted otherwise in the changelog
Borg 1.x.y upgrades
Use borg upgrade --tam REPO to require manifest authentication introduced with Borg 1.0.9 to address
security issues. This means that modifying the repository after doing this with a version prior to 1.0.9
will raise a validation error, so only perform this upgrade after updating all clients using the
repository to 1.0.9 or newer.
This upgrade should be done on each client for safety reasons.
If a repository is accidentally modified with a pre-1.0.9 client after this upgrade, use borg upgrade
--tam --force REPO to remedy it.
If you routinely do this you might not want to enable this upgrade (which will leave you exposed to the
security issue). You can reverse the upgrade by issuing borg upgrade --disable-tam REPO.
See https://borgbackup.readthedocs.io/en/stable/changes.html#pre-1-0-9-manifest-spoofing-vulnerability
for details.
Attic and Borg 0.xx to Borg 1.x
This currently supports converting an Attic repository to Borg and also helps with converting Borg 0.xx
to 1.0.
Currently, only LOCAL repositories can be upgraded (issue #465).
Please note that borg create (since 1.0.0) uses bigger chunks by default than old borg or attic did, so
the new chunks won't deduplicate with the old chunks in the upgraded repository. See --chunker-params
option of borg create and borg recreate.
borg upgrade will change the magic strings in the repository's segments to match the new Borg magic
strings. The keyfiles found in $ATTIC_KEYS_DIR or ~/.attic/keys/ will also be converted and copied to
$BORG_KEYS_DIR or ~/.config/borg/keys.
The cache files are converted, from $ATTIC_CACHE_DIR or ~/.cache/attic to $BORG_CACHE_DIR or
~/.cache/borg, but the cache layout between Borg and Attic changed, so it is possible the first backup
after the conversion takes longer than expected due to the cache resync.
Upgrade should be able to resume if interrupted, although it will still iterate over all segments. If you
want to start from scratch, use borg delete over the copied repository to make sure the cache files are
also removed:
borg delete borg
Unless --inplace is specified, the upgrade process first creates a backup copy of the repository, in
REPOSITORY.upgrade-DATETIME, using hardlinks. This takes longer than in place upgrades, but is much safer
and gives progress information (as opposed to cp -al). Once you are satisfied with the conversion, you
can safely destroy the backup copy.
WARNING: Running the upgrade in place will make the current copy unusable with older version, with no way
of going back to previous versions. This can PERMANENTLY DAMAGE YOUR REPOSITORY! Attic CAN NOT READ BORG
REPOSITORIES, as the magic strings have changed. You have been warned.
Examples
# Upgrade the borg repository to the most recent version.
$ borg upgrade -v /path/to/repo
making a hardlink copy in /path/to/repo.upgrade-2016-02-15-20:51:55
opening attic repository with borg and converting
no key file found for repository
converting repo index /path/to/repo/index.0
converting 1 segments...
converting borg 0.xx to borg current
no key file found for repository
Upgrading a passphrase encrypted attic repo
attic offered a "passphrase" encryption mode, but this was removed in borg 1.0 and replaced by the
"repokey" mode (which stores the passphrase-protected encryption key into the repository config).
Thus, to upgrade a "passphrase" attic repo to a "repokey" borg repo, 2 steps are needed, in this order:
• borg upgrade repo
• borg migrate-to-repokey repo
BORG BREAK-LOCK
usage: borg break-lock [-h] [--critical] [--error] [--warning] [--info]
[--debug] [--lock-wait N] [--show-rc]
[--no-files-cache] [--umask M] [--remote-path PATH]
[REPOSITORY]
Break the repository lock (e.g. in case it was left by a dead borg.
positional arguments:
REPOSITORY repository for which to break the locks
optional arguments:
-h, --help show this help message and exit
--critical work on log level CRITICAL
--error work on log level ERROR
--warning work on log level WARNING (default)
--info, -v, --verbose
work on log level INFO
--debug work on log level DEBUG
--lock-wait N wait for the lock, but max. N seconds (default: 1).
--show-rc show/log the return code (rc)
--no-files-cache do not load/update the file metadata cache used to
detect unchanged files
--umask M set umask to M (local and remote, default: 0077)
--remote-path PATH use PATH as borg executable on the remote (default:
"borg")
Description
This command breaks the repository and cache locks. Please use carefully and only while no borg process
(on any machine) is trying to access the Cache or the Repository.
MISCELLANEOUS HELP
borg help patterns
Exclusion patterns support four separate styles, fnmatch, shell, regular expressions and path prefixes.
By default, fnmatch is used. If followed by a colon (':') the first two characters of a pattern are used
as a style selector. Explicit style selection is necessary when a non-default style is desired or when
the desired pattern starts with two alphanumeric characters followed by a colon (i.e. aa:something/*).
Fnmatch, selector fm:
This is the default style. These patterns use a variant of shell pattern syntax, with '*' matching
any number of characters, '?' matching any single character, '[...]' matching any single character
specified, including ranges, and '[!...]' matching any character not specified. For the purpose of
these patterns, the path separator ('' for Windows and '/' on other systems) is not treated specially.
Wrap meta-characters in brackets for a literal match (i.e. [?] to match the literal character ?). For
a path to match a pattern, it must completely match from start to end, or must match from the start to
just before a path separator. Except for the root path, paths will never end in the path separator
when matching is attempted. Thus, if a given pattern ends in a path separator, a '*' is appended
before matching is attempted.
Shell-style patterns, selector sh:
Like fnmatch patterns these are similar to shell patterns. The difference is that the pattern may
include **/ for matching zero or more directory levels, * for matching zero or more arbitrary
characters with the exception of any path separator.
Regular expressions, selector re:
Regular expressions similar to those found in Perl are supported. Unlike shell patterns regular
expressions are not required to match the complete path and any substring match is sufficient. It is
strongly recommended to anchor patterns to the start ('^'), to the end ('$') or both. Path separators
('' for Windows and '/' on other systems) in paths are always normalized to a forward slash ('/')
before applying a pattern. The regular expression syntax is described in the Python documentation for
the re module.
Prefix path, selector pp:
This pattern style is useful to match whole sub-directories. The pattern pp:/data/bar matches
/data/bar and everything therein.
NOTE:
re:, sh: and fm: patterns are all implemented on top of the Python SRE engine. It is very easy to
formulate patterns for each of these types which requires an inordinate amount of time to match paths.
If untrusted users are able to supply patterns, ensure they cannot supply re: patterns. Further,
ensure that sh: and fm: patterns only contain a handful of wildcards at most.
Exclusions can be passed via the command line option --exclude. When used from within a shell the
patterns should be quoted to protect them from expansion.
The --exclude-from option permits loading exclusion patterns from a text file with one pattern per line.
Lines empty or starting with the number sign ('#') after removing whitespace on both ends are ignored.
The optional style selector prefix is also supported for patterns loaded from a file. Due to whitespace
removal paths with whitespace at the beginning or end can only be excluded using regular expressions.
Examples:
# Exclude '/home/user/file.o' but not '/home/user/file.odt':
$ borg create -e '*.o' backup /
# Exclude '/home/user/junk' and '/home/user/subdir/junk' but
# not '/home/user/importantjunk' or '/etc/junk':
$ borg create -e '/home/*/junk' backup /
# Exclude the contents of '/home/user/cache' but not the directory itself:
$ borg create -e /home/user/cache/ backup /
# The file '/home/user/cache/important' is *not* backed up:
$ borg create -e /home/user/cache/ backup / /home/user/cache/important
# The contents of directories in '/home' are not backed up when their name
# ends in '.tmp'
$ borg create --exclude 're:^/home/[^/]+\.tmp/' backup /
# Load exclusions from file
$ cat >exclude.txt <<EOF
# Comment line
/home/*/junk
*.tmp
fm:aa:something/*
re:^/home/[^/]\.tmp/
sh:/home/*/.thumbnails
EOF
$ borg create --exclude-from exclude.txt backup /
borg help placeholders
Repository (or Archive) URLs, --prefix and --remote-path values support these placeholders:
{hostname}
The (short) hostname of the machine.
{fqdn}
The full name of the machine.
{now}
The current local date and time.
{utcnow}
The current UTC date and time.
{user}
The user name (or UID, if no name is available) of the user running borg.
{pid}
The current process ID.
{borgversion}
The version of borg, e.g.: 1.0.8rc1
{borgmajor}
The version of borg, only the major version, e.g.: 1
{borgminor}
The version of borg, only major and minor version, e.g.: 1.0
{borgpatch}
The version of borg, only major, minor and patch version, e.g.: 1.0.8
Examples:
borg create /path/to/repo::{hostname}-{user}-{utcnow} ...
borg create /path/to/repo::{hostname}-{now:%Y-%m-%d_%H:%M:%S} ...
borg prune --prefix '{hostname}-' ...
DEBUG COMMANDS
There are some more commands (all starting with "debug-") which are all not intended for normal use and
potentially very dangerous if used incorrectly.
For example, borg debug-put-obj and borg debug-delete-obj will only do what their name suggests: put
objects into repo / delete objects from repo.
Please note:
• they will not update the chunks cache (chunks index) about the object
• they will not update the manifest (so no automatic chunks index resync is triggered)
• they will not check whether the object is in use (e.g. before delete-obj)
• they will not update any metadata which may point to the object
They exist to improve debugging capabilities without direct system access, e.g. in case you ever run
into some severe malfunction. Use them only if you know what you are doing or if a trusted Borg developer
tells you what to do.
ADDITIONAL NOTES
Here are misc. notes about topics that are maybe not covered in enough detail in the usage section.
Item flags
borg create -v --list outputs a verbose list of all files, directories and other file system items it
considered (no matter whether they had content changes or not). For each item, it prefixes a
single-letter flag that indicates type and/or status of the item.
If you are interested only in a subset of that output, you can give e.g. --filter=AME and it will only
show regular files with A, M or E status (see below).
A uppercase character represents the status of a regular file relative to the "files" cache (not relative
to the repo -- this is an issue if the files cache is not used). Metadata is stored in any case and for
'A' and 'M' also new data chunks are stored. For 'U' all data chunks refer to already existing chunks.
• 'A' = regular file, added (see also a_status_oddity in the FAQ)
• 'M' = regular file, modified
• 'U' = regular file, unchanged
• 'E' = regular file, an error happened while accessing/reading this file
A lowercase character means a file type other than a regular file, borg usually just stores their
metadata:
• 'd' = directory
• 'b' = block device
• 'c' = char device
• 'h' = regular file, hardlink (to already seen inodes)
• 's' = symlink
• 'f' = fifo
Other flags used include:
• 'i' = backup data was read from standard input (stdin)
• '-' = dry run, item was not backed up
• '?' = missing status code (if you see this, please file a bug report!)
--chunker-params
The chunker params influence how input files are cut into pieces (chunks) which are then considered for
deduplication. They also have a big impact on resource usage (RAM and disk space) as the amount of
resources needed is (also) determined by the total amount of chunks in the repository (see Indexes /
Caches memory usage for details).
--chunker-params=10,23,16,4095 results in a fine-grained deduplication and creates a big amount of chunks
and thus uses a lot of resources to manage them. This is good for relatively small data volumes and if
the machine has a good amount of free RAM and disk space.
--chunker-params=19,23,21,4095 (default) results in a coarse-grained deduplication and creates a much
smaller amount of chunks and thus uses less resources. This is good for relatively big data volumes and
if the machine has a relatively low amount of free RAM and disk space.
If you already have made some archives in a repository and you then change chunker params, this of course
impacts deduplication as the chunks will be cut differently.
In the worst case (all files are big and were touched in between backups), this will store all content
into the repository again.
Usually, it is not that bad though:
• usually most files are not touched, so it will just re-use the old chunks it already has in the repo
• files smaller than the (both old and new) minimum chunksize result in only one chunk anyway, so the
resulting chunks are same and deduplication will apply
If you switch chunker params to save resources for an existing repo that already has some backup
archives, you will see an increasing effect over time, when more and more files have been touched and
stored again using the bigger chunksize and all references to the smaller older chunks have been removed
(by deleting / pruning archives).
If you want to see an immediate big effect on resource usage, you better start a new repository when
changing chunker params.
For more details, see chunker_details.
--noatime / --noctime
You can use these borg create options to not store the respective timestamp into the archive, in case you
do not really need it.
Besides saving a little space for the not archived timestamp, it might also affect metadata stream
deduplication: if only this timestamp changes between backups and is stored into the metadata stream, the
metadata stream chunks won't deduplicate just because of that.
--umask
If you use --umask, make sure that all repository-modifying borg commands (create, delete, prune) that
access the repository in question use the same --umask value.
If multiple machines access the same repository, this should hold true for all of them.
--read-special
The --read-special option is special - you do not want to use it for normal full-filesystem backups, but
rather after carefully picking some targets for it.
The option --read-special triggers special treatment for block and char device files as well as FIFOs.
Instead of storing them as such a device (or FIFO), they will get opened, their content will be read and
in the backup archive they will show up like a regular file.
Symlinks will also get special treatment if (and only if) they point to such a special file: instead of
storing them as a symlink, the target special file will get processed as described above.
One intended use case of this is backing up the contents of one or multiple block devices, like e.g. LVM
snapshots or inactive LVs or disk partitions.
You need to be careful about what you include when using --read-special, e.g. if you include /dev/zero,
your backup will never terminate.
Restoring such files' content is currently only supported one at a time via --stdout option (and you have
to redirect stdout to where ever it shall go, maybe directly into an existing device file of your choice
or indirectly via dd).
To some extent, mounting a backup archive with the backups of special files via borg mount and then
loop-mounting the image files from inside the mount point will work. If you plan to access a lot of data
in there, it likely will scale and perform better if you do not work via the FUSE mount.
Example
Imagine you have made some snapshots of logical volumes (LVs) you want to backup.
NOTE:
For some scenarios, this is a good method to get "crash-like" consistency (I call it crash-like
because it is the same as you would get if you just hit the reset button or your machine would
abrubtly and completely crash). This is better than no consistency at all and a good method for some
use cases, but likely not good enough if you have databases running.
Then you create a backup archive of all these snapshots. The backup process will see a "frozen" state of
the logical volumes, while the processes working in the original volumes continue changing the data
stored there.
You also add the output of lvdisplay to your backup, so you can see the LV sizes in case you ever need to
recreate and restore them.
After the backup has completed, you remove the snapshots again.
$ # create snapshots here
$ lvdisplay > lvdisplay.txt
$ borg create --read-special /path/to/repo::arch lvdisplay.txt /dev/vg0/*-snapshot
$ # remove snapshots here
Now, let's see how to restore some LVs from such a backup.
$ borg extract /path/to/repo::arch lvdisplay.txt
$ # create empty LVs with correct sizes here (look into lvdisplay.txt).
$ # we assume that you created an empty root and home LV and overwrite it now:
$ borg extract --stdout /path/to/repo::arch dev/vg0/root-snapshot > /dev/vg0/root
$ borg extract --stdout /path/to/repo::arch dev/vg0/home-snapshot > /dev/vg0/home
Append-only mode
A repository can be made "append-only", which means that Borg will never overwrite or delete committed
data. This is useful for scenarios where multiple machines back up to a central backup server using borg
serve, since a hacked machine cannot delete backups permanently.
To activate append-only mode, edit the repository config file and add a line append_only=1 to the
[repository] section (or edit the line if it exists).
In append-only mode Borg will create a transaction log in the transactions file, where each line is a
transaction and a UTC timestamp.
In addition, borg serve can act as if a repository is in append-only mode with its option --append-only.
This can be very useful for fine-tuning access control in .ssh/authorized_keys
command="borg serve --append-only ..." ssh-rsa <key used for not-always-trustable backup clients>
command="borg serve ..." ssh-rsa <key used for backup management>
Please note that if you run borg init via a borg serve --append-only server, the repository config will
be created with a append_only=1 entry. This behaviour is subject to change in a later borg version. So,
be aware of it for now, but do not rely on it.
Example
Suppose an attacker remotely deleted all backups, but your repository was in append-only mode. A
transaction log in this situation might look like this:
transaction 1, UTC time 2016-03-31T15:53:27.383532
transaction 5, UTC time 2016-03-31T15:53:52.588922
transaction 11, UTC time 2016-03-31T15:54:23.887256
transaction 12, UTC time 2016-03-31T15:55:54.022540
transaction 13, UTC time 2016-03-31T15:55:55.472564
From your security logs you conclude the attacker gained access at 15:54:00 and all the backups where
deleted or replaced by compromised backups. From the log you know that transactions 11 and later are
compromised. Note that the transaction ID is the name of the last file in the transaction. For example,
transaction 11 spans files 6 to 11.
In a real attack you'll likely want to keep the compromised repository intact to analyze what the
attacker tried to achieve. It's also a good idea to make this copy just in case something goes wrong
during the recovery. Since recovery is done by deleting some files, a hard link copy (cp -al) is
sufficient.
The first step to reset the repository to transaction 5, the last uncompromised transaction, is to remove
the hints.N and index.N files in the repository (these two files are always expendable). In this example
N is 13.
Then remove or move all segment files from the segment directories in data/ starting with file 6:
rm data/**/{6..13}
That's all to it.
Drawbacks
As data is only appended, and nothing removed, commands like prune or delete won't free disk space, they
merely tag data as deleted in a new transaction.
Be aware that as soon as you write to the repo in non-append-only mode (e.g. prune, delete or create
archives from an admin machine), it will remove the deleted objects permanently (including the ones that
were already marked as deleted, but not removed, in append-only mode).
Note that you can go back-and-forth between normal and append-only operation by editing the configuration
file, it's not a "one way trip".
Further considerations
Append-only mode is not respected by tools other than Borg. rm still works on the repository. Make sure
that backup client machines only get to access the repository via borg serve.
Ensure that no remote access is possible if the repository is temporarily set to normal mode for e.g.
regular pruning.
Further protections can be implemented, but are outside of Borgs scope. For example, file system
snapshots or wrapping borg serve to set special permissions or ACLs on new data files.
SSH batch mode
When running Borg using an automated script, ssh might still ask for a password, even if there is an SSH
key for the target server. Use this to make scripts more robust:
export BORG_RSH='ssh -oBatchMode=yes'
AUTHOR
The Borg Collective (see AUTHORS file)
COPYRIGHT
2010-2014 Jonas Borgström, 2015-2019 The Borg Collective (see AUTHORS file)