This page presents my choices to build a NAS with

  • a large number of disks (6 to 10)
  • a low power consumption
  • a good redundancy
  • an affordable price (about 700$)

Technology

Choices

  • RAIDZ2
  • ZFS

Operating system

  • FreeNAS
  • ZFS support
  • good documentation
  • good forum
  • actively developed

Hardware

UPS

Motherboard + CPU

Criteria

  • large number of SATA
  • high memory
  • wake-on-LAN
  • low power (< 50W)

Quad core

Main features:

  • mini itx
  • Intel Avoton C2550 Quad Core 2.4GHZ featuring 14W TDP
  • 16 Go per slot, 64 max, 4 slots
  • 12 SATA (4 SATA2, 8 SATA3)
  • IPMI
  • 3 USB port (1 for UPS, 1 for freenas)

Octa core

RAM ECC

  • ECC is highly recommended for ZFS
  • compatibility
  • Choice: DDR3 1600 ECC 8GB Crucial CT102472BD160B.

Chassis

Criteria

  • good cooling, dust filters
  • large space
  • large number of HDD 3.5" slots
  • compatible with mini itx board

Choice:

Main features:

  • PSU ATX/EPS
  • 2 SSD slots (on the side)
  • 8 HDD slots (3.5" or 2.5")
  • 2 slots for optical drives (that we can convert to 3.5" or 2.5" slots)
  • 2 fans 140mm included
  • additional slots for fans
  • rubber on the disk slots to avoid vibrations

 PSU

Consider only high quality to avoid power variations that could damage the disks.

Selection:

  • FSP AURUM S400 400W 80PLUS Gold
  • Enermax Revolution XT ERX430AWT 80PLUS Gold

I choose FSP (cheaper and good enough).

USB key

  • SanDisk Cruzer Fit 16 Go

Pro:

  • cheap
  • freenas requires 8 GB, the key is much larger
  • short length (5 mm), something we can forget behind the box.

HDD

I consider

  • old HDD (in a good shape...)
  • slow speed (5400 rpm), lower power, lower temperature
  • WD red, I have a good experience with them.

Extra considerations:

  • the space is limited by the smallest disk
  • it is impossible to add disks to a vdev. Be smart now! :)
  • it will be too difficult to make 2 vdev with this configuration (for RAIDZ2)
  • how much will it cost (given the disk you already have) to replace the smaller HDD to gain space?

Cables

  • The motherboard is shipped with 6 SATA cables.
  • The PSU has a limited number of SATA power slots (5). Extensions are needed.

SSD

It's not clear that it's necessary (cf reddit or Introduction to vdev, zpool, ZIL, L2ARC). It is advised to put the maximum of RAM first.

Ressources