How to Build a Minimal ZFS NAS Without Synology, QNAP, TrueNAS (2024)

Original Article ↗ Hacker News Discussion ↗

Home server enthusiasts weigh the trade-offs between building a minimal ZFS-based NAS on generic hardware versus buying turnkey appliances like Synology or TrueNAS. Comments range from practical hardware advice (used enterprise boxes, low-power mini-PCs, SAS vs SATA, avoiding USB enclosures) to deeper debates over ZFS on Linux vs FreeBSD/illumos, ECC RAM “requirements,” RAID level choices, and SSD/HDD reliability. Many note that soaring storage prices and AI-driven hardware demand make timing and design decisions more painful, while emphasizing that snapshots, scrubs, offsite backups, and tested recovery plans matter more than any single stack choice.

Hardware and Form Factor Choices

  • Many use older enterprise gear (Dell PowerEdge, HP ProLiant MicroServers, HP workstations, ThinkCentre mini PCs) for ECC, iDRAC/IPMI, and many bays; downside is noise, size, and higher idle power.
  • Others prefer compact, low‑power “true home” hardware: mini‑PCs (e.g. N100‑class, Lenovo tiny PCs) or Raspberry Pi 5 with HATs; concern is limited bays and often no ECC.
  • USB multi‑bay enclosures are widely reported as flaky for important data (overheating adapters, disconnects, missing TRIM), especially with ZFS.

ZFS vs Appliances (Synology/TrueNAS/Unraid)

  • Pro‑appliance camp values: hot‑swap trays, LEDs/beeps for failed disks, integrated UI, replication, cloud sync, HA, monitoring, “don’t let me type the wrong command”.
  • DIY ZFS camp argues: ZFS itself is the “proven reliable system”, with better design than mdadm/LVM; disk replacement is usually just zpool replace.
  • Several report more data loss or compromise on off‑the‑shelf NASes than on DIY, but others distrust “hacky” setups for critical data.

ZFS on Linux vs FreeBSD/illumos

  • One side: running ZFS on Debian/Linux is “second‑class”, an out‑of‑tree module subject to kernel breakage and GPL hostility; recommends FreeBSD or illumos (OmniOS+napp-it) as most solid.
  • Counterpoint: OpenZFS targets Linux first; Linux and FreeBSD share the same ZFS code; running on LTS kernels is stable in practice. TrueNAS moving from BSD to Debian is cited.
  • Some note issues on Debian/Proxmox with NVMe under ZFS; others report long‑term success on many Linux and BSD systems.

Drives, RAID Levels, and Capacity Concerns

  • Ongoing “crisis” in disk and SSD pricing; many shuck external HDDs or buy used SAS enterprise drives for better $/TB.
  • RAIDZ1 vs RAIDZ2 vs mirrors:
    • RAIDZ2 favored to avoid data loss from read errors during resilver on large disks.
    • Some say RAIDZ1 is fine at home if you have real backups.
  • ZFS free‑space rule (keep ~20% free) is debated: some see real performance loss and fragmentation past 90%; others report near‑full pools working fine, especially with large files.
  • Consumer SSDs in RAIDZ are warned against by some due to lower endurance and small overprovisioning; others say they work but need headroom and care.

Backups, Monitoring, and Failure Handling

  • Strong consensus: snapshots and scrubs are essential; schedule regular scrubs and monitor zpool status.
  • Alerts are critical: email via smartmontools/smartctl_exporter, cron, or similar; relying only on MOTD or manual checks is seen as unsafe.
  • Guides that omit “a disk failed, here is how to detect and replace it” and alerting are criticized as incomplete.
  • Multiple tools for ZFS snapshot/backup automation mentioned (e.g. sanoid, zfs-backup), plus zfs send/receive, rsync.net, zfs.rent.
  • One user recounts losing all NAS data because they hadn’t tested recovery and lost their encryption config; “test disaster recovery” is heavily emphasized.

Alternatives to ZFS

  • Some prefer:
    • Btrfs on MDADM.
    • dm‑integrity + mdadm + XFS for a simpler, non‑ZFS stack.
    • SnapRAID + mergerfs for large mostly‑static media (more flexible disk sizes, easy drive removal).
    • Unraid for home servers; generally positive feedback for simplicity.
    • LVM with snapshots (noted to differ fundamentally from ZFS snapshots and require size management).
  • RHEL/Rocky + Cockpit, Proxmox (with ZFS and Proxmox Backup Server), and NixOS are popular bases for DIY NASes, each trading simplicity, tooling, and ecosystem differences.

AI and Storage Prices (Tangent)

  • Several posters blame current high storage and RAM prices on the AI boom; some say they would gladly give up modern LLMs to return to cheaper hardware and less “slop” content. Others see AI as transformative enough to justify the temporary pain.