Raspberry Pi NAS

Network Attached Storage (NAS) made from a MyBook Duo RAID drive and a Raspberry Pi.

Features:

• The storage consists of a Western Digital MyBook Duo drive, which contains two WD Red drives in a USB 3.0 cabinet. They are available in different sizes, currently up to 20TB. Here I chose the 8TB version which consists of two 4TB drives.
• The network attached controller is a Raspberry Pi 3B, which has a 4-core 1.2GHz ARM processor, 1GB non-ECC RAM, USB 2.0, and 100Base-TX ethernet. It also has built-in Wifi, but for typical use-cases you would presumably connect it to the router with an ethernet cable.
• Power consumtion for the MyBook Duo drive is 4W when idle, and 18W when active. This increases to about 21W when connected via USB 3.0, but the Raspberry Pi uses USB 2.0 only. Power consumtion for the Raspberry Pi is approximately 2-4W depending on the load. So in total it's about 6-22W depending on activity.

Setup requires first connecting the MyBook Duo to a Mac (a PC running Windows should work too, I guess) where you configure it to use RAID-1 using the Western Digital software. Then connect it to the Raspberry Pi or another Linux computer and partition it using gdisk. The RAID volume will show up as a single USB drive. Then create a file system (or several) on the partition(s).

The Raspberry Pi boots from a microSD card. This makes it very convenient to upgrade the OS, since I can easily clone the card and upgrade and test the clone on a different Raspberry Pi before switching. My initial OS is Raspbian "stretch" from 2018-11-13.

The beauty of this approach compared to buying a proprietary NAS is that you can use any file system supported by Linux, and you can tweak the configurations for NFS, Samba, FTP, etc to your heart's delight. And it's easy to also run a DNS resolver on it, a local mail relay, a WWW server, an IRC server, or whatever you like.

Note: this replaces an older much more heavy-weight custom NAS server from 2010.