Organazing home backup system

Written by skeirss

I've organized my first home automated backup system and tried my best to describe it (the system seems a bit complicated to me, so in case something goes wrong I'll definitely need a reference). Since this is my first attempt at setting up a backup system, it may have some flaws.

Backup System Documentation

TL;DR

  • All backups are stored on NAS (192.168.88.40)
  • Storage path: /srv/backups, /mnt/media/backups (for media)
  • Tools: borg + borgmatic + bash scripts
  • Clients: arch-pc, vps-nl, NAS itself
  • Check status: systemctl status borgmatic.timer
  • Logs: journalctl -u borgmatic.service
  • Restore: see "Restore" section

Architecture

[arch-pc] ──(borgmatic.timer -> daily at 22:00)──borgmatic {/etc/borgmatic.d/arch-pc.yaml} ──▶ [NAS]──/srv/backups/arch-pc (Samsung SSD)

[vps-nl] ──(borgmatic.timer -> daily at 16:00 Server time (21:00 EKT))──borgmatic {/etc/borgmatic/config.yaml} ──▶ [NAS]──/srv/backups/vps-nl (Samsung SSD)

[arch-pc-media] ──media-backup.sh (running manually)──borgmatic {/etc/borgmatic.d/arch-pc-media.yaml} ──▶ [NAS]──/mnt/media/backups/arch-pc-media (External HDD)

[nas] ──(borgmatic.timer)──borgmatic {/etc/borgmatic/config.yaml}──▶ /srv/backups/nas (Samsung SSD)

Networking

arch-pc → NAS
  • Direct SSH connection
  • SSH Alias: home-borg (described in /root/.ssh/config)
  • Path: ssh://home-borg/srv/backups/arch-pc
arch-pc-media → NAS
VPS → NAS
  • Reverse SSH tunnel (described in /etc/systemd/system/ssh-tunnel-persistent_amsterdam.service)
  • Mapping: VPS localhost:2233 → NAS:3315
  • SSH Alias: home-borg (described in /root/.ssh/config)
  • Path: ssh://home-borg/srv/backups/vps-nl
NAS → NAS
  • No network, direct data transfer

Storage Layout

/srv/backups/

arch-pc/

vps-nl/

nas/

/run/media/bernd/backups/

arch-pc-media/

Archive format: {hostname}-{timestamp}

Monitoring

Notifications:

  • Telegram bot

Triggers:

  • success
  • failure

Script:

  • /usr/local/bin/send_message_tg.sh

Restore

List archives: borg list /path/to/repo or outside the NAS: borgmatic repo-list --config /etc/borgmatic.d/arch-pc.yaml

Mount the archive to /mnt/borg (*): sudo borgmatic mount --config /etc/borgmatic.d/arch-pc.yaml --archive archpc-2025-10-03T21:25:12 --mount-point /mnt/borg

Unmount: sudo borgmatic umount --mount-point /mnt/borg

Extract a file from the archive: sudo borgmatic extract --config /etc/borgmatic.d/arch-pc.yaml --archive archpc-2025-10-03T21:25:12 --path /path/to/file/to/extact --destination /tmp

Restore all files from the archive: borgmatic extract --config /etc/borgmatic.d/arch-pc.yaml --archive archpc-2025-10-03T21:25:12

(*) fuse2 and python-llfuse packages should be installed

DB restore

The borgmatic configuration file used for the original backup must be available on the host.

Case 1. Restore all configured databases from the latest archive: /root/.local/bin/borgmatic restore --config /etc/borgmatic/config.yaml --archive latest

Case 2. Restore a specific database (e.g., only Bookstack’s MariaDB): 1) Stop all containers that use the mariadb container, e.g.: docker stop bookstack; 2) borgmatic restore --config /etc/borgmatic/config.yaml --archive latest --database bookstack

Case 3. Restore only the Chyrp-lite SQLite database: 1) Stop the container; 2) /root/.local/bin/borgmatic restore --config /etc/borgmatic/config.yaml --archive latest --database chyrp

Troubleshooting

Case 1. borg.crypto.key.ArchiveTAMInvalid: Data integrity error: Archive authentication did not verify error when trying to open an archive

Solution: This problem is related to Trusted Archive Metadata (TAM). The solution is to repair the archives:

su - 

BORG_WORKAROUNDS=ignore_invalid_archive_tam borg upgrade --archives-tam /path/to/repo

Check: borg check /path/to/repo

To-Do

  • Docker containers configs + DB backup and restore (done)
  • There are two weak points in the current setup: the NAS backing up to itself (so this is not really a backup, just versioning), and the lack of an offsite backup. Both issues could be addressed by periodically copying backup archives to an encrypted external drive stored elsewhere.