Three years ago I bought 2 sets of Synology 1812+‘s for work. They’ve done pretty well (8x3TB drives in SHR2 configuration, with about 5-6 drive swaps between them). Overall, my experience with the Synology’s have been good, although I’ve been a bit frustrating by the slowness/unreliability of doing partial (rsync/rsnapshot-style) syncs between them, and rsync performance in general was quite bad, mostly due to underpowered processing.

Over the past few years (2014, 2011, 2008) I’ve looked at (and passed) on building a ZFS NAS, but this time I decided to take the plunge.

There are quite a few ZFS NAS specific distros that are available. The most popular is FreeNAS. There’s actually quite a few resources on building your own ZFS NAS so I’ll just do a link-dump first:

• Louwrentius: Why I Do Use ZFS as a File System for My NAS – a good starting point on pros/cons and various options for ZFS. For actual ZFS benefits, you’ll want to read Should I Use ZFS for My DIY Home NAS? and The ‘Hidden’ Cost of Using ZFS for Your Home NAS, and Things You Should Consider When Building a ZFS NAS. If you’re into storage/ZFS, pretty much all the posts on the blog are great and worth a read.
• DIY NAS: 2016 Edition – the author of this has been building and writing about his DIY NAS’s for a few years now. The article is admirably detailed, with lots of interesting details and some good stats. I went with different hardware (the cache SSD added expense and complexity without moving the performance needle, and the Avoton board was both overpriced and under-powered) so my build ended up being cheaper, better performing, and surprisingly, consuming less power both idle and when transferring data.
• FreeNAS Box (2016) – another guide that had a bunch of good pointers and a bunch of links for further reading
• Building ZFS Based Network Attached Storage Using FreeNAS 8 – the UI has changed a bit, but the screenshots and step-by-step were useful
• Building a NAS Server – this guide is older (2011), but still a nice writeup
• FreeNAS Home Server Build – another guide, focused on hardware

The main notes for my NAS build is that rather than going for a 5 or 8 drive case (one of the tougher things to find), I went w/ a 4 drive build with the Seagate 8TB Archive drives, which isn’t really recommended for NAS use and has some mixed performance, but for our purposes (basically, write-once archival use) it seemed like it’d be fine (and so far has been), and brought the cost/GB to $0.05/GB (the drives themselves are $0.028/GB vs $0.036/GB for the 4TB NAS drives).

Some numbers:

• 5.5W w/ Power Off (there is an always-on IPMI management system, that’s quite useful); was able to use this to assist in tracking down a boot issue on assembly when the CPU power wasn’t plugged in (it’s not next to the main board power)
• With no drives (besides an internally plugged 16GB USB boot stick) it boots at 50W and idles at around 31W
• With 4 x 8TB Seagate Archive drives plugged in (20.4TiB RAID-Z1) it idles at around 57W. Copying a big file over via CIFS/SMB, it hits about 75MB/s out of the box, and power is about 79-80W during the transfer
• The machine takes about 1m40s to being network accessible, and about 2m20s until services (web, samba) are up. Shutdown from FreeNAS web click to power off is 45s.

One last thing, if you’re interested in building a ZFS NAS but not so interested in the hardware bits, it may be worth taking a look at HP’s ProLiant MicroServer Gen8 which often go on sale/can be found cheap and have decent specs for a storage box.