The wonderful 'dar' Disk Archiver is used for the heavy lifting, together with the par2 suite in these scripts.
This is the Python based version 2 of dar-backup.
dar-backup is a Python-powered CLI for creating and validating full, differential, and incremental backups using dar and par2. Designed for long-term restore integrity, even on user-space filesystems like FUSE.
- Full, differential or incremental backups using 'dar'
- My use case
- License
- Changelog version 2
- Status
- Homepage - Github
- Community
- Requirements
- Principles
- How to run
- Config
- Systemd examples
- List contents of an archive
- dar file selection examples
- Restoring
- Par2
- Points of interest
- Todo
- Known Limitations / Edge Cases
- Reference
I have cloud storage mounted on a directory within my home dir. The filesystem is FUSE based, which gives it a few special features
- a non-privileged user can perform a mount
- a privileged user cannot look into the filesystem --> a backup script running as root is not suitable
I needed the following:
- Backup my cloud storage to something local (cloud is convenient, but I want control over my backups)
- Backup primarily photos, video and different types of documents
- Have a simple non-complicated way of restoring, possibly years into the future. 'dar' fits that scenario with a single statically linked binary (kept with the archives). There is no need install/configure anything - restoring is simple and works well.
- During backup archives must be tested and a restore test (however small) performed
- Archives stored on a server with a reliable file system (easy to mount a directory over sshfs)
- Easy to verify archive's integrity, after being moved around.
I do not need the encryption features of dar, as all storage is already encrypted.
These scripts are licensed under the GPLv3 license. Read more here: GNU CPL 3.0, or have a look at the "LICENSE" file in this repository.
As of August 8, 2024 I am using the alpha versions of dar-backup (alpha-0.5.9 onwards) in my automated backup routine.
As of February 13, 2025, I have changed the status from alpha --> beta, as the featureset is in place and the alphas have worked well for a very long time.
To increase the security and authenticity of dar-backup packages, all releases from v2-beta-0.6.18 onwards will be digitally signed using the GPG key below.
🔐 GPG Signing Key Details
Name: Per Jensen (author of dar-backup)
Email: dar-backup@pm.me
Primary key: 4592 D739 6DBA EFFD 0845 02B8 5CCE C7E1 6814 A36E
Signing key: B54F 5682 F28D BA36 22D7 8E04 58DB FADB BBAC 1BB1
Created: 2025-03-29
Expires: 2030-03-28
Key type: ed25519 (primary, SC)
Subkeys: ed25519 (S), ed25519 (A), cv25519 (E)
🔏 Where to Find Release Signatures
PyPI does Not host .asc Signature Files
Although the dar-backup packages on PyPI are GPG-signed, PyPI itself does not support uploading .asc detached signature files alongside .whl and .tar.gz artifacts.
Therefore, you will not find .asc files on PyPI.
✅ Where to Get .asc Signature Files
You can always download the signed release artifacts and their .asc files from the official GitHub Releases page:
📁 GitHub Releases for dar-backup
Each release includes:
-
dar_backup-x.y.z.tar.gz -
dar_backup-x.y.z.tar.gz.asc -
dar_backup-x.y.z-py3-none-any.whl -
dar_backup-x.y.z-py3-none-any.whl.asc
🔐 How to Verify a Release from GitHub
-
Import the GPG public key:
curl https://keys.openpgp.org/vks/v1/by-fingerprint/4592D7396DBAEFFD084502B85CCEC7E16814A36E | gpg --import -
Download the wheel or tarball and its .asc signature from the GitHub.
-
Run GPG to verify it:
gpg --verify dar_backup-x.y.z.tar.gz.asc dar_backup-x.y.z.tar.gz # or gpg --verify dar_backup-x.y.z-py3-none-any.whl.asc dar_backup-x.y.z-py3-none-any.whl -
If the signature is valid, you'll see:
gpg: Good signature from "Per Jensen (author of dar-backup) <dar-backup@pm.me>"
🛡️ Reminder: Verify the signing subkey
Only this subkey is used to sign PyPI packages:
B54F 5682 F28D BA36 22D7 8E04 58DB FADB BBAC 1BB1
You can view it with:
gpg --list-keys --with-subkey-fingerprints dar-backup@pm.meVersion 0.6.0 and forwards requires the config variable COMMAND_TIMEOUT_SECS in the config file.
'dar-backup' package lives here: Github - dar-backup
This python version is v2 of dar-backup, v1 is made in bash.
Please review the Code of Conduct to help keep this project welcoming and focused.
- dar
- par2
- python3
On Ubuntu, install the requirements this way:
sudo apt install dar par2 python3dar-backup is built in a way that emphasizes getting backups. It loops over the backup definitions, and in the event of a failure while backing up a backup definition, dar-backup shall log an error and start working on the next backup definition.
There are 3 levels of backups, FULL, DIFF and INCR.
-
The author does a FULL yearly backup once a year. This includes all files in all directories as defined in the backup definition(s) (assuming
-dwas not given). -
The author makes a DIFF once a month. The DIFF backs up new and changed files compared to the FULL backup.
- No DIFF backups are taken until a FULL backup has been taken for a particular backup definition.
-
The author takes an INCR backup every 3 days. An INCR backup includes new and changed files compared to the DIFF backup.
-
So, a set of INCR's will contain duplicates (this might change as I become more used to use the catalog databases)
-
No INCR backups are taken until a DIFF backup has been taken for a particular backup definition.
-
After each backup of a backup definition, dar-backup tests the archive and then performs a few restore operations of random files from the archive (see dar-backup.conf). The restored files are compared to the originals to check if the restore went well.
dar-backup skips doing a backup of a backup definition if an archive is already in place. So, if you for some reason need to take a new backup on the same date, the first archive must be deleted (I recommend using cleanup).
The cleanup application deletes DIFF and INCR if the archives are older than the thresholds set up in the configuration file.
cleanup will only remove FULL archives if the option --cleanup-specific-archives is used. It requires the user to confirm deletion of FULL archives.
darhas the concept of catalogs which can be exported and optionally be added to a catalog database. That database makes it much easier to restore the correct version of a backed up file if for example a target date has been set.
dar-backup adds archive catalogs to their databases (using the manager script). Should the operation fail, dar-backup logs an error and continue with testing and restore validation tests.
📦 All official dar-backup releases from v2-beta-0.6.18 are signed with GPG.
See more here.
Installation is currently in a venv. These commands are installed in the venv:
- dar-back
- cleanup
- manager
- clean-log
- installer
Note:
The module inputimeout is installed into the venv and used for the confirmation input (with a 30 second timeout)
To install, create a venv and run pip:
mkdir $HOME/tmp
cd $HOME/tmp
python3 -m venv venv # create the virtual environment
. venv/bin/activate # activate the virtual env
pip install dar-backup # run pip to install `dar-backup`I have an alias in ~/.bashrc pointing to my venv:
alias db=". ~/tmp/venv/bin/activate; dar-backup -v"Typing db at the command line gives this
(venv) user@machine:~$ db
dar-backup 0.6.12
dar-backup.py source code is here: https://github.com/per2jensen/dar-backup
Licensed under GNU GENERAL PUBLIC LICENSE v3, see the supplied file "LICENSE" for details.
THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW, not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
See section 15 and section 16 in the supplied "LICENSE" file.The dar-backup installer is non-destructive and stops if some of the default directories exist.
Run the installer
installer --installThe output is
Directories created: `/home/user/dar-backup/` and `/home/user/.config/dar-backup`
Config file deployed to /home/user/.config/dar-backup/dar-backup.conf
Default backup definition deployed to /home/user/.config/dar-backup/backup.d/default
1. Now run `manager --create-db` to create the catalog database.
2. Then you can run `dar-backup --full-backup` to create a backup.
3. List backups with `dar-backup --list`
4. List contents of a backup with `dar-backup --list-contents <backup-name>`
Generate the archive catalog database(s).
dar-backup expects the catalog databases to be in place, it does not automatically create them (by design)
manager --create-dbPrereq: Backup definitions are in place in BACKUP.D_DIR (see config file).
You are ready to do backups of all your backup definitions.
dar-backup --full-backup If you want to see dar-backup's log entries in the terminal, use the --log-stdout option. This can be useful if dar-backup is started by systemd.
If you want more log messages, use the --verbose or --log-level debug for even more.
If you want a backup of a single definition, use the -d <backup definition> option. The definition's name is the filename of the definition in the backup.d config directory.
dar-backup --full-backup -d <your backup definition>Deactivate the virtual environment (venv)
deactivateThe configuration file's default location is: ~/.config/dar-backup/dar-backup.conf
If you have your config file somewhere else, use the --config option to point to it.
Tilde ~ and environment variables can be used in the paths for various file locations.
[MISC]
LOGFILE_LOCATION=~/.dar-backup.log
MAX_SIZE_VERIFICATION_MB = 20
MIN_SIZE_VERIFICATION_MB = 1
NO_FILES_VERIFICATION = 5
# timeout in seconds for backup, test, restore and par2 operations
# The author has such `dar` tasks running for 10-15 hours on the yearly backups, so a value of 24 hours is used.
# If a timeout is not specified when using the util.run_command(), a default timeout of 30 secs is used.
COMMAND_TIMEOUT_SECS = 86400
[DIRECTORIES]
BACKUP_DIR = /some/where/dar-backup/backups/
BACKUP.D_DIR = /some/where/dar-backup/backup.d
TEST_RESTORE_DIR = /tmp/dar-backup/restore/
[AGE]
# age settings are in days
DIFF_AGE = 100
INCR_AGE = 40
[PAR2]
ERROR_CORRECTION_PERCENT = 5
ENABLED = True
# scripts to run before the backup to setup the environment
[PREREQ]
SCRIPT_1 = ls -l /tmp
#SCRIPT_2 = another_script.sh
[POSTREQ]
SCRIPT_1 = df -h
#SCRIPT_2 = another_script.sh
The package includes a default darrc file which configures dar.
You can override the default .darrc using the --darrc option.
The default .darrc contents are as follows:
# .darrc configuration file for `dar` as used by the `dar-backup` script.
# `dar-backup` lives here: https://github.com/per2jensen/dar-backup
##############################################################
# target: verbose
# remove comments belov for dar being more verbose
verbose:
# shows files teated due to filtering inclusion or no filtering at all
# -vt
# shows skipped files du to exclusion
# -vs
# shows diretory currently being processed
# dar-backup logs `dar` stdout in real time, so directories being processed are now shown in the log file.
# this is quite useful in long running jobs
-vd
# shows detailed messages, not related to files and directories
# -vm
# shows summary of each treated directory, including average compression
# dar-backup logs `dar` stdout in real time, so directories being processed are now shown in the log file.
# this is quite useful in long running jobs
-vf
# equivalent to "-vm -vs -vt"
# -va
restore-options:
# don't restore File Specific Attributes
#--fsa-scope none
# ignore owner, useful when used by a non-privileged user
--comparison-field=ignore-owner
# Exclude specific file types from compression
compress-exclusion:
# First setting case insensitive mode on:
-an
-ag
-Z "*.gz"
-Z "*.bz2"
-Z "*.xz"
-Z "*.zip"
-Z "*.rar"
-Z "*.7z"
-Z "*.tar"
-Z "*.tgz"
-Z "*.tbz2"
-Z "*.txz"
# Exclude common image file types from compression
-Z "*.jpg"
-Z "*.jpeg"
-Z "*.png"
-Z "*.gif"
-Z "*.bmp"
-Z "*.tiff"
-Z "*.svg"
-Z "*.ico"
-Z "*.webp"
# The author uses Nikon compressed NEFs raw files
-Z "*.NEF"
# Exclude common movie file types from compression
-Z "*.mp4"
-Z "*.avi"
-Z "*.mkv"
-Z "*.mov"
-Z "*.wmv"
-Z "*.flv"
-Z "*.mpeg"
-Z "*.mpg"
# These are zip files. Not all are compressed, but considering that they can
# get quite large it is probably more prudent to leave this uncommented.
-Z "*.pk3"
-Z "*.zip"
-Z "*.lz4"
-Z "*.zoo"
-Z "*.Po"
-Z "*.aar"
-Z "*.bx"
-Z "*.chm"
-Z "*.doc"
-Z "*.epub"
-Z "*.f3d"
-Z "*.gpg"
-Z "*.htmlz"
-Z "*.iix"
-Z "*.iso"
-Z "*.jin"
-Z "*.ods"
-Z "*.odt"
-Z "*.ser"
-Z "*.svgz"
-Z "*.swx"
-Z "*.sxi"
-Z "*.whl"
-Z "*.wings"
# Dar archives (may be compressed).
-Z "*.dar"
# Now we swap back to case sensitive mode for masks which is the default
#mode:
-acase
This piece of configuration is a backup definition. It is placed in the BACKUP.D_DIR (see config file description). The name of the file is the name of the backup definition.
You can use as many backup definitions as you need.
# Switch to ordered selection mode, which means that the following
# options will be considered top to bottom
-am
# Backup Root Dir
# This is the top directory, where the backups start.
#Directories mentioned below, are relative to the Root Dir.
-R /home/user/
# Directories to backup below the Root dir
# uncomment the next line to backup only the Documents directory
# -g Documents
# Directories to exclude below the Root dir
-P mnt
-P tmp
-P .cache
-P .config/Code/CachedData
# compression level
-z5
# no overwrite, if you rerun a backup, 'dar' halts and asks what to do
# due to the -Q option given to `dar`, the program will terminate and give en error.
-n
# size of each slice in the archive
--slice 7G
# bypass directores marked as cache directories
# http://dar.linux.free.fr/doc/Features.html
# https://bford.info/cachedir/
--cache-directory-tagging
The command dar-backup-systemd can generate and optionally install systemd units and timers.
The timers are set as the author uses them, modify to your taste and needs.
Example run:
dar-backup-systemd --venv /home/user/tmp/venv --dar-path /home/user/.local/dar/bin
Generated dar-full-backup.service and dar-full-backup.timer
→ Fires on: *-12-30 10:03:00
Generated dar-diff-backup.service and dar-diff-backup.timer
→ Fires on: *-*-01 19:03:00
Generated dar-incr-backup.service and dar-incr-backup.timer
→ Fires on: *-*-04/3 19:03:00
Generated dar-clean.service and dar-clean.timer
→ Fires on: *-*-* 21:07:00I have dar-backup scheduled to run via systemd --user settings.
The files are located in: ~/.config/systemd/user
Once the .service and .timer files are in place, timers must be enabled and started.
systemctl --user enable dar-inc-backup.timer
systemctl --user start dar-inc-backup.timer
systemctl --user daemon-reloadVerify your timers are set up as you want:
systemctl --user list-timersThis is an exmaple of a systemd user service unit.
File: dar-incr-backup.service
/tmp/test$ dar-backup-systemd --venv '$HOME/programmer/dar-backup.py/venv' --dar-path '$HOME/.local/dar/bin'
Generated dar-full-backup.service and dar-full-backup.timer
→ Fires on: *-12-30 10:03:00
Generated dar-diff-backup.service and dar-diff-backup.timer
→ Fires on: *-*-01 19:03:00
Generated dar-incr-backup.service and dar-incr-backup.timer
→ Fires on: *-*-04/3 19:03:00
Generated dar-cleanup.service and dar-cleanup.timer
→ Fires on: *-*-* 21:07:00
/tmp/test$
(venv) /tmp/test$
(venv) /tmp/test$ cat dar-incr-backup.service
[Unit]
Description=dar-backup INCR
StartLimitIntervalSec=120
StartLimitBurst=1
[Service]
Type=oneshot
TimeoutSec=infinity
RemainAfterExit=no
ExecStart=/bin/bash -c 'PATH=$HOME/.local/dar/bin:$PATH && . $HOME/programmer/dar-backup.py/venv/bin/activate && dar-backup -I --verbose --log-stdout'This is an example of a systemd user timer
File: dar-incr-backup.timer
[Unit]
Description=dar-backup INCR timer
[Timer]
OnCalendar=*-*-04/3 19:03:00
Persistent=true
[Install]
WantedBy=timers.target
📅 OnCalendar syntax is flexible — you can tweak backup schedules easily. Run systemd-analyze calendar to preview timers.
. <the virtual evn>/bin/activate
dar-backup --list-contents example_FULL_2024-06-23 --selection "-X '*.xmp' -I '*2024-06-16*' -g home/pj/tmp/LUT-play"
deactivategives
[Data ][D][ EA ][FSA][Compr][S]| Permission | User | Group | Size | Date | filename
--------------------------------+------------+-------+-------+---------+-------------------------------+------------
[Saved][-] [-L-][ 0%][ ] drwxr-xr-x root root 113 Mio Sat May 11 16:16:48 2024 home
[Saved][-] [-L-][ 0%][ ] drwxrwxr-x pj pj 113 Mio Sun Jun 23 10:46:30 2024 home/pj
[Saved][-] [-L-][ 0%][ ] drwxrwxr-x pj pj 113 Mio Sun Jun 23 09:17:42 2024 home/pj/tmp
[Saved][-] [-L-][ 1%][ ] drwxrwxr-x pj pj 50 Mio Wed Jun 19 20:52:13 2024 home/pj/tmp/LUT-play
[Saved][ ] [-L-][ 0%][X] -rw-rw-r-- pj pj 49 Mio Sun Jun 16 12:52:22 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15.NEF
dar -l /tmp/example_FULL_2024-06-23 -g home/pj/tmp/LUT-playgives
[Data ][D][ EA ][FSA][Compr][S]| Permission | User | Group | Size | Date | filename
--------------------------------+------------+-------+-------+---------+-------------------------------+------------
[Saved][-] [-L-][ 0%][ ] drwxr-xr-x root root 113 Mio Sat May 11 16:16:48 2024 home
[Saved][-] [-L-][ 0%][ ] drwxrwxr-x pj pj 113 Mio Sun Jun 23 10:46:30 2024 home/pj
[Saved][-] [-L-][ 0%][ ] drwxrwxr-x pj pj 113 Mio Sun Jun 23 09:17:42 2024 home/pj/tmp
[Saved][-] [-L-][ 1%][ ] drwxrwxr-x pj pj 50 Mio Wed Jun 19 20:52:13 2024 home/pj/tmp/LUT-play
[Saved][ ] [-L-][ 0%][X] -rw-rw-r-- pj pj 49 Mio Sun Jun 16 12:52:22 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15.NEF
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 48 kio Sat Jun 22 21:51:24 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 50 kio Sat Jun 22 21:51:25 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_01.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 51 kio Sat Jun 22 21:51:26 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_02.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 51 kio Sat Jun 22 21:51:27 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_03.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 51 kio Sat Jun 22 21:51:27 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_04.NEF.xmp
[Saved][ ] [-L-][ 97%][ ] -rw-rw-r-- pj pj 77 kio Sat Jun 22 21:50:16 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_05.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 52 kio Sat Jun 22 21:49:37 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_06.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:47 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_07.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:51:12 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_08.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:51:12 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_09.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:39 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_10.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:36 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_11.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:35 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_12.NEF.xmp
[Saved][ ] [-L-][ 88%][ ] -rw-rw-r-- pj pj 15 kio Sat Jun 22 21:51:11 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_13.NEF.xmp
[Saved][ ] [-L-][ 96%][ ] -rw-rw-r-- pj pj 84 kio Sat Jun 22 21:51:09 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_14.NEF.xmp
[Saved][ ] [-L-][ 96%][ ] -rw-rw-r-- pj pj 90 kio Sat Jun 22 21:51:04 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_15.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:51:15 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_16.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:48 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_17.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:19 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_18.NEF.xmp
dar -l /tmp/example_FULL_2024-06-23 -I '*2024-06-16*' -g home/pj/tmp/LUT-playgives
[Data ][D][ EA ][FSA][Compr][S]| Permission | User | Group | Size | Date | filename
--------------------------------+------------+-------+-------+---------+-------------------------------+------------
[Saved][-] [-L-][ 0%][ ] drwxr-xr-x root root 113 Mio Sat May 11 16:16:48 2024 home
[Saved][-] [-L-][ 0%][ ] drwxrwxr-x pj pj 113 Mio Sun Jun 23 10:46:30 2024 home/pj
[Saved][-] [-L-][ 0%][ ] drwxrwxr-x pj pj 113 Mio Sun Jun 23 09:17:42 2024 home/pj/tmp
[Saved][-] [-L-][ 1%][ ] drwxrwxr-x pj pj 50 Mio Sed Jun 19 20:52:13 2024 home/pj/tmp/LUT-play
[Saved][ ] [-L-][ 0%][X] -rw-rw-r-- pj pj 49 Mio Sun Jun 16 12:52:22 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15.NEF
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 48 kio Sat Jun 22 21:51:24 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 50 kio Sat Jun 22 21:51:25 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_01.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 51 kio Sat Jun 22 21:51:26 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_02.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 51 kio Sat Jun 22 21:51:27 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_03.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 51 kio Sat Jun 22 21:51:27 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_04.NEF.xmp
[Saved][ ] [-L-][ 97%][ ] -rw-rw-r-- pj pj 77 kio Sat Jun 22 21:50:16 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_05.NEF.xmp
[Saved][ ] [-L-][ 95%][ ] -rw-rw-r-- pj pj 52 kio Sat Jun 22 21:49:37 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_06.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:47 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_07.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:51:12 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_08.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:51:12 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_09.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:39 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_10.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:36 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_11.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:35 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_12.NEF.xmp
[Saved][ ] [-L-][ 88%][ ] -rw-rw-r-- pj pj 15 kio Sat Jun 22 21:51:11 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_13.NEF.xmp
[Saved][ ] [-L-][ 96%][ ] -rw-rw-r-- pj pj 84 kio Sat Jun 22 21:51:09 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_14.NEF.xmp
[Saved][ ] [-L-][ 96%][ ] -rw-rw-r-- pj pj 90 kio Sat Jun 22 21:51:04 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_15.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:51:15 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_16.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:48 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_17.NEF.xmp
[Saved][ ] [-L-][ 92%][ ] -rw-rw-r-- pj pj 24 kio Sat Jun 22 21:50:19 2024 home/pj/tmp/LUT-play/2024-06-16_12:52:22,15_18.NEF.xmp
dar -l /tmp/example_FULL_2024-06-23 -X '*.xmp' -I '*2024-06-16*' -g home/pj/tmp/LUT-play
gives
[Data ][D][ EA ][FSA][Compr][S]| Permission | User | Group | Size | Date | filename
--------------------------------+------------+-------+-------+---------+-------------------------------+------------
[Saved][-] [-L-][ 0%][ ] drwxr-xr-x root root 113 Mio Sat May 11 16:16:48 2024 home
[Saved][-] [-L-][ 0%][ ] drwxrwxr-x pj pj 113 Mio Sun Jun 23 10:46:30 2024 ome/pj
[Saved][-] [-L-][ 0%][ ] drwxrwxr-x pj pj 113 Mio Sun Jun 23 09:17:42 2024 ome/pj/tmp
[Saved][-] [-L-][ 1%][ ] drwxrwxr-x pj pj 50 Mio Wed Jun 19 20:52:13 2024 ` ome/pj/tmp/LUT-play
[Saved][ ] [-L-][ 0%][X] -rw-rw-r-- pj pj 49 Mio Sun Jun 16 12:52:22 2024 ` home/pj/tmp/LUT-play/2024-06-16_12:52:22,15.NEF
dar-backup will use the TEST_RESTORE_DIR location as the Root for restores, if the --restore-dir option has not been supplied.
See example below to see where files are restored to.
When the --restore-dir option is used for restoring, a directory must be supplied.
The directory supplied functions as the Root of the restore operation.
Example:
A backup has been taken using this backup definition:
-R /
-g home/user/Documents
When restoring and using /tmp for --restore-dir, the restored files can be found in /tmp/home/user/Documents
. <the virtual env>/bin/activate
dar-backup --restore <archive_name> --selection "-g path/to/file"
deactivate
. <the virtual env>/bin/activate
dar-backup --restore <archive_name> --selection "-g path/to/directory"
deactivate. <the virtual env>/bin/activate
dar-backup --restore <archive_name> --selection "-X '*.xmp' -I '*2024-06-16*' -g home/pj/tmp/LUT-play"
deactivate"dar" in newer versions emits a question about file ownership, which is "answered" with a "no" via the "-Q" option. That in turn leads to an error code 4.
Thus the dar option "--comparison-field=ignore-owner" has been placed in the supplied .darrc file (located in the virtual environment where dar-backup is installed).
This causes dar to restore without an error.
It is a good option when using dar as a non-privileged user.
If exit code 5 is emitted on the restore test, FSA (File System specific Attributes) could be the cause.
That (might) occur if you backup a file stored on one type of filesystem, and restore it on another type. My home directory is on a btrfs filesystem, while /tmp (for the restore test) is on zfs.
The restore test can result in an exit code 5, due to the different filesystems used. In order to avoid the errors, the "option "--fsa-scope none" can be used. That will restult in FSA's not being restored.
If you need to use this option, un-comment it in the .darrc file (located in the virtual environment where dar-backup is installed)
You can run a par2 verification on an archive like this:
for file in <archive>*.dar.par2; do
par2 verify "$file"
doneif there are problems with a slice, try to repair it like this:
par2 repair <archive>.<slice number>.dar.par2If you have merged archives, you will need to create the .par2 redundency files manually. Here is an example
for file in <some-archive>_FULL_yyyy-mm-dd.*; do
par2 c -r5 -n1 "$file"
donewhere "c" is create, -r5 is 5% redundency and -n1 is 1 redundency file
Over time, the DIFF archives become larger and larger. At some point one wishes to create a new FULL archive to do DIFF's on. One way to do that, is to let dar create a FULL archive from scratch, another is to merge a FULL archive with a DIFF, and from there do DIFF's until they once again gets too large for your taste.
I do backups of my homedir. Here it is shown how a FULL archive is merged with a DIFF, creating a new FULL archive.
dar --merge pj-homedir_FULL_2021-09-12 -A pj-homedir_FULL_2021-06-06 -@pj-homedir_DIFF_2021-08-29 -s 12G
# test the new FULL archive
dar -t pj-homedir_FULL_2021-09-12
# create Par2 redundancy files
for file in pj-homedir_FULL_yyyy-mm-dd.*.dar; do
par2 c -r5 -n1 "$file"
donedar-backup now saves archive catalogs in dar catalog databases.
This makes it easier to restore to a given date when having many FULL, DIFF and INCR archives.
If the manager does not add an archive to it's catalog database, dar-backup will log an error and continue. The important part is verify the archive is usable and continue to other backup definitions.
This dar benchmark page has an interesting note on the slice size.
Slice size should be smaller than available RAM, apparently a large performance hit can be avoided keeping the par2 data in memory.
These .darrc settings make dar print the current directory being processed (-vd) and some stats after (-vf)
This is very useful in very long running jobs to get an indication that the backup is proceeding normally.
Dar-backup's log file is called dar-backup.log.
In order to not clutter that log file with the output of commands being run, a new secondary log file has been introduced dar-backup-commands.log.
The secondary log file can get quite cluttered, if you want to remove the clutter, run the clean-logscript with the --file option, or simply delete it.
The author uses the --cache-directory-tagging option in his backup definitions.
The effect is that directories with the CACHEDIR.TAG file are not backed up. Those directories contain content fetched from the net, which is of an ephemeral nature and probably not what you want to back up.
If the option is not in the backup definition, the cache directories are backed up as any other.
If you run dar-backup interactively in a "normal" console on your computer, dar-backup displays 2 visual artifacts to show progress.
- a progress bar that fills up and starts over
- a status line showing the directory being backed up. If the directory is big and takes time to backup, the line is not changing, but you will probably know there is a lot to backup.
The indicators are not shown if dar-backup is run from systemd or if it is used in terminal multiplexers like tmux or screen. So no polluting of journald logs.
The dar-backup, manager, and cleanup scripts now support dynamic Bash tab-completion, making them easier and faster to use.
✅ Features
-
Autocomplete for all long options (--config-file, --restore, etc.)
-
Dynamic suggestions based on your config:
-
--backup-definition shows available definitions from backup.d/
-
show relevant archives when a backup definition has been chosen:
dar-backup: --restore, --list-contents, and --alternate-reference-archive
cleanup: --cleanup-specific-archives
manager: --list-archive-contents, --add-specific-archive (autocomplete those *not in the catalog database), --remove-specific-archive
-
Supports paths like ~ and $HOME correctly
Try typing:
dar-backup --<TAB>You should see all available flags like --full-backup, --restore, etc.
Try completion of backup definition and then list contents:
dar-backup --backup-definition <TAB>
dar-backup -d <the chosen backup-definition> --list-contents <TAB>When using manager--list-archive-contents, the tab-completer suggests valid archive names.
The behavior is smart and context-aware:
-
If a --backup-definition (-d) is provided, archive suggestions are restricted to that .db catalog.
-
If no backup definition is given, the completer will:
-
Scan all .db files in the backup_dir
-
Aggregate archive names across all catalogs
-
Sort results by:
-
Backup name (e.g. pCloudDrive, media-files)
-
Date inside the archive name (e.g. 2025-04-19)
-
-
It’s blazing fast and designed for large backup sets.
# With a backup definition
manager -d pCloudDrive --list-archive-contents <TAB>
# ⤷ Suggests: pCloudDrive_FULL_2025-03-04, pCloudDrive_INCR_2025-04-19, ...
# Without a backup definition
manager --list-archive-contents <TAB>
# ⤷ Suggests: all archives across all known backup definitions
# ⤷ Example: media-files_FULL_2025-01-04, pCloudDrive_INCR_2025-04-19, ...
# Filter by prefix
manager --list-archive-contents media-<TAB>
# ⤷ Suggests: media-files_FULL_2025-01-04, media-files_INCR_2025-02-20, ...Try auto completion in your session:
eval "$(register-python-argcomplete dar-backup)"
eval "$(register-python-argcomplete cleanup)"
eval "$(register-python-argcomplete manager)"To make it persistent across sessions, add this to your ~/.bashrc:
# Enable autocompletion for dar-backup
eval "$(register-python-argcomplete dar-backup)"
eval "$(register-python-argcomplete cleanup)"
eval "$(register-python-argcomplete manager)"Then reload your shell:
source ~/.bashrcIf you're using Zsh, add this to your .zshrc:
autoload -U bashcompinit
bashcompinit
eval "$(register-python-argcomplete dar-backup)"
eval "$(register-python-argcomplete cleanup)"
eval "$(register-python-argcomplete manager)"Then reload Zsh:
source ~/.zshrc- When run interactively, a progress bar during test and par2 generation would be nice.
- Look into a way to move the .par2 files away from the
darslices, to maximize chance of good redundancy. - Add option to dar-backup to use the
daroption--fsa-scope none
Does not currently encrypt data (by design — relies on encrypted storage)
One backup definition per file
.par2 files created for each slice (may be moved in future)
- The wonderful dar achiver
- The Parchive suite
- shellcheck - a bash linter
- Ubuntu of course :-)
- PyPI
- Tracking PyPI downloads with pypi-total-downloads-tracker
| Command | Description |
|---|---|
dar-backup |
Perform full, differential, or incremental backups with verification and restore testing |
manager |
Maintain and query catalog databases for archives |
cleanup |
Remove outdated DIFF/INCR archives (and optionally FULLs) |
clean-log |
Clean up excessive log output from dar command logs |
installer |
Set up required directories and default config files |
dar-backup-systemd |
Generate (and optionally install) systemd timers and services for automated backups |
Running
pytest --cov=dar_backup tests/Results for a version 0.6.19 in this report:
Name Stmts Miss Cover
----------------------------------------------------------
src/dar_backup/__about__.py 1 0 100%
src/dar_backup/__init__.py 0 0 100%
src/dar_backup/clean_log.py 68 13 81%
src/dar_backup/cleanup.py 196 17 91%
src/dar_backup/command_runner.py 80 3 96%
src/dar_backup/config_settings.py 66 7 89%
src/dar_backup/dar_backup.py 539 56 90%
src/dar_backup/dar_backup_systemd.py 56 7 88%
src/dar_backup/installer.py 59 6 90%
src/dar_backup/manager.py 403 54 87%
src/dar_backup/rich_progress.py 70 7 90%
src/dar_backup/util.py 231 24 90%
----------------------------------------------------------
TOTAL 1769 194 89%
This script does backups including par2 redundancy, validation and restoring.
Available options:
-F, --full-backup Perform a full backup.
-D, --differential-backup Perform a differential backup.
-I, --incremental-backup Perform an incremental backup.
-d, --backup-definition <name> Specify the backup definition file.
--alternate-reference-archive <file> Use a different archive for DIFF/INCR backups.
-c, --config-file <path> Specify the path to the configuration file.
--darrc <path> Specify an optional path to .darrc.
--examples Show examples of using dar-backup.py.
-l, --list List available backups.
--list-contents <archive> List the contents of a specified archive.
--selection <params> Define file selection for listing/restoring.
--restore <archive> Restore a specified archive.
-r, --restore-dir <path> Directory to restore files to.
--verbose Enable verbose output.
--suppress-dar-msg Filter out this from the darrc: "-vt", "-vs", "-vd", "-vf", "-va"
--log-level <level> `debug` or `trace`, default is `info`.
--log-stdout Also print log messages to stdout.
--do-not-compare Do not compare restores to file system.
-v, --version Show version and license information.This script manages dar databases and catalogs.
Available options:
-c, --config-file <path> Path to dar-backup.conf.
--create-db Create missing databases for all backup definitions.
--alternate-archive-dir <path> Use this directory instead of BACKUP_DIR in the config file.
--add-dir <path> Add all archive catalogs in this directory to databases.
-d, --backup-def <name> Restrict operations to this backup definition.
--add-specific-archive <archive> Add a specific archive to the catalog database.
--remove-specific-archive <archive> Remove a specific archive from the catalog database.
-l, --list-catalogs List catalogs in databases for all backup definitions.
--list-archive-contents <archive> List the contents of an archive’s catalog by archive name.
--find-file <file> Search catalogs for a specific file.
--verbose Enable verbose output.
--log-level <level> Set log level (`debug` or `trace`, default is `info`).This script removes old backups and par2 files according to [AGE] settings in config file.
Catalogs in catalog databases are also removed.
Supported options:
-d, --backup-definition Backup definition to cleanup.
-c, --config-file Path to 'dar-backup.conf'
-v, --version Show version & license information.
--alternate-archive-dir Clean up in this directory instead of the default one.
--cleanup-specific-archives "<archive>, <>, ..." Comma separated list of archives to cleanup.
-l, --list List available archives (filter using the -d option).
--verbose Print various status messages to screen.
--log-level <level> `debug` or `trace`, default is `info`", default="info".
--log-stdout Print log messages to stdout.
--test-mode This is used when running pytest test casesThis script removes excessive logging output from dar logs, improving readability and efficiency. Available options:
-f, --file <path> Specify the log file(s) to be cleaned.
-c, --config-file <path> Path to dar-backup.conf.
--dry-run Show which lines would be removed without modifying the file.
-v, --version Display version and licensing information.
-h, --help Displays usage infoSets up dar-backupfor a user.
It is non-destructive and stops if directories are already in place.
Create directories:
- ~/.config/dar-backup/
- ~/.config/dar-backup/backup.d/
- ~/dar-backup/
- ~/dar-backup/backups
- ~/dar-backup/restore
Sets up demo config files:
- ~/.config/dar-backup/dar-backup.conf
- ~/.config/dar-backup/backup.d/default
-i, --install Sets up `dar-backup`.
-v, --version Display version and licensing information.
-h, --help Displays usage infoGenerates and optionally install systemd user service units and timers.
-h, --help Show this help message and exit
--venv VENV Path to the Python venv with dar-backup
--dar-path DAR_PATH Optional path to dar binary's directory
--install Install the units to ~/.config/systemd/user