Restic backup service and timer configuration

To use, copy or link these files to:

/usr/lib/systemd/user

then enable them as user services with systemd:

systemctl --user enable restic-backup.service
systemctl --user enable restic-backup.timer
systemctl --user enable restic-backup-remote.service
systemctl --user enable restic-backup-remote.timer

Set up automated backup locally and to Backblaze B2 using restic on Arch Linux

1. Use your package manager to install restic from the Community repository or the AUR

2. Follow the instructions for creating a repo here. Create both a local and a Backblaze repo.

3. Create a file containing the repo's password in a secure location and set the appropriate permissions

4. If you want to exclude certain directories and files, you can create an exclude file using the instructions here.

5. Create a script for running the backup with restic. In the script you will need to set the environment parameters for the B2_ACCOUNT_ID and B2_ACCOUNT_KEY required to access Backblaze B2.

   #!/usr/bin/env bash
   
   export B2_ACCOUNT_ID="YOUR_ID"
   export B2_ACCOUNT_KEY="YOUR_KEY"
   export RESTIC_PASSWORD_FILE=/path/to/your/password
   
   restic -r /your/backup/location backup --verbose /folder/to/backup --exclude-file=/path/to/your/exclude-file
   restic -r b2:your-b2-bucket:/your/b2/backup-folder backup --verbose /folder/to/backup --exclude-file=/path/to/your/exclude-file

6. Arch uses the systemd timer schedules as an alternative to cron. In order to automate the backups, we need to set up a user systemd service and a systemd timer and enable both. The service will execute the script we created in the step above to perform the backups, but only as your user rather than a system-wide service.

7. Create a service file in /usr/lib/systemd/user. We will call this service file restic-backup.service:

   [Unit]
   Description=Backup locally and to Backblaze B2 using Restic
   
   [Service]
   ExecStart=/path/to/your/backup-script
   
   [Install]
   WantedBy=default.target

8. Create a timer file in /user/lib/systemd/user. We will call this service file restic-backup.timer:

   [Unit]
   Description=Run restic backup locally and to Backblaze B2 every hour
   
   [Timer]
   # Time to wait after booting before we run first time
   OnBootSec=1h
   # If you want to run it every hour after the job has started
   # OnUnitActiveSec=1h
   # If you want to run on the hour, every hour
   OnCalendar=00/1:00
   Unit=restic-backup.service        # This is the systemd service you created to do the backups
   
   [Install]
   WantedBy=timers.target

9. Test your service to make sure everything works properly, the watch command allows us to monitor the status of the service without having to issue the systemctl status command repeatedly:

   systemctl --user start restic-backup.service
   watch systemctl --user status restic-backup.service

10. If everything is working correct, you can to start and enable the timer:

    systemctl --user start restic-backup.timer
    systemctl --user enable restic-backup.timer

11. You should cleanup your snapshots periodically to save disk space. This is done with restic forget and restic prune. The forget command removes the snapshot, but doesn't delete the underlying data. To clean the underlying data you must use the prune command. References to how restic selects which snapshots to forget can be found here. To do this, create another script:

    #!/usr/bin/env bash
    
    export B2_ACCOUNT_ID="YOUR_ID"
    export B2_ACCOUNT_KEY="YOUR_KEY"
    export RESTIC_PASSWORD_FILE=/path/to/your/password
    
    restic -r /your/backup/location forget --keep-daily 7 --keep-weekly 4 --keep-monthly 12
    restic -r b2:your-b2-bucket:/your/b2/backup-folder forget --keep-daily 7 --keep-weekly 4 --keep-monthly 12
    restic -r /your/backup/location prune
    restic -r b2:your-b2-bucket:/your/b2/backup-folder forget

12. Now you can create another service and timer file using the instructions above and create an appropriate schedule for cleaning up your backups.

    [Unit]
    Description=Clean up restic backups from local cache and to Backblaze B2 every Sunday
    
    [Timer]
    # Time to wait after booting before we run first time
    OnBootSec=1h
    # Run every Sunday at 1AM
    OnCalendar=Sun *-*-* 01:00:00
    # In the event the job wasn't run at the last scheduled time, i.e. the machine was off etc.
    Persistent=true
    Unit=restic-cleanup.service
    
    [Install]
    WantedBy=timers.target