Part 3 of 3. Use a dedicated NAS or Raspberry Pi to host ultra-reliable Time Machine backups with snapshot and RAID options.
Why choose a NAS or Pi?
- 24/7 reliability and smart power management
- Snapshots and versioning (Synology Btrfs, ZFS, etc.)
- RAID for drive redundancy
- Web UI setup in minutes (Synology/QNAP) or full DIY control (Pi + Samba)
Synology DSM (5-minute setup)
- Control Panel → File Services → SMB → Enable SMB.
- Enable Advanced SMB Settings then tick Enable Time Machine service [web:77].
- Create a shared folder (e.g.,
timemachine) and set a Quota. - macOS → Time Machine → Add Backup Disk → choose NAS share.
Raspberry Pi (Samba + Avahi)
- Flash Raspberry Pi OS Lite; update packages.
sudo apt install samba avahi-daemon- Format external USB drive:
sudo mkfs.ext4 /dev/sda1; mount at/srv/timemachine. - Add Samba share with
fruit:time_machine = yes. - Create tmuser; set share permissions.
- Add Avahi service file to advertise Time Machine.
Power & noise considerations
A Pi 4 idles at ≈3 W; a two-bay NAS draws 15–25 W. Factor electricity cost vs. convenience.
Troubleshooting
| Issue | Fix |
|---|---|
| Backups disconnect | Use Ethernet, check SMB signing offload |
| “Disk full” message | Increase share quota or prune snapshots |
| Pi overheats | Add heatsink/fan; place in ventilated area |
When to choose dedicated hardware
- Multiple Macs need large, concurrent backups
- You want RAID and snapshot protection
- Noise/power draw is acceptable
Return to the complete guide or revisit Part 1 / Part 2.
Updated: September 20 2025