media-backup-systemd

systemd-based backup of Raspberry Pi media server (mediaserver.lan) to backup server (backupserver.lan) using rsync.

Consists of two timer-based systemd jobs:

• media_permissions - fixes the permissions on the media server to ensure that the backup can work properly (runs every day at 1am)
• media_backup - uses rsync to sync media folder on media server with one on the backup server (runs every day at 2am)

systemd services/timers based on this tutorial.

Backup user

Create a user pibak for handling the backup operation.

NB: Adjust numeric group/user IDs as appropriate.

Media server

• create group pibak: groupadd -g 1002 pibak
• create user pibak: useradd pibak -u 1001 -g 1002 -m -s /bin/bash
• log in as user pibak
• create ssh key (no passphrase): ssh-keygen
• output public key: cat ~/.ssh/id_rsa.pub

Backup server

• create group pibak: groupadd -g 1002 pibak
• create user pibak: useradd pibak -u 1001 -g 1002 -m -s /bin/bash
• log in as user pibak
• paste the media-server public key into: ~/.ssh/authorized_keys

Scripts (media server)

Fixing permissions

#!/bin/bash

chown pi:users /media/xbmc/media
find /media/xbmc/media -type d -exec chmod 775 {} \;

Syncing media files

#!/bin/bash

# rsync files to backup server for at most 2h
timeout 120m rsync -av --delete --rsh=ssh --modify-window=3601 /media/xbmc/media/ backupserver.lan:/media/backup/media/xbmc

Systemd (media server)

• located in /etc/systemd/system
• media_permissions.service

  [Unit]
  Description="Fixes the permissions of the media files and directories."
  
  [Service]
  ExecStart=/usr/local/bin/media_permissions.sh
  

• media_permissions.timer

  [Unit]
  Description="Run media_permissions.service every night at 1am"
  
  [Timer]
  OnCalendar=Mon..Sun *-*-* 01:00:*
  Unit=media_permissions.service
  
  [Install]
  WantedBy=multi-user.target
  

• media_backup.service

  [Unit]
  Description="Backs up the media to backupserver.lan"
  
  [Service]
  User=pibak
  Group=pibak
  ExecStart=/usr/local/bin/media_backup.sh
  

• media_backup.timer

  [Unit]
  Description="Run media_backup.service every night at 2am"
  
  [Timer]
  OnCalendar=Mon..Sun *-*-* 02:00:*
  Unit=media_backup.service
  
  [Install]
  WantedBy=multi-user.target
  

• verify systemd jobs: systemd-analyze verify /etc/systemd/system/media_.*
• enable system timers:

  systemctl enable media_permissions.timer
  systemctl enable media_backup.timer