I bought a Wyse Z90DW thin client on eBay for the cost of a Raspberry Pi. I am going to use it as an inexpensive NAS (network attached storage device). To do that I needed a caddy to hold hard drives as the case has no provisions for them. I will probably buy more and run a distributed file system like GlusterFS or Ceph but FreeNAS would also be an excellent choice.
With these specs it is much more robust than a Raspberry Pi:
I designed the caddy to be easy to install, hold one or two hard drives, and not require a bunch of case modding. The rounded feet slide into place easily and the whole thing is held in place by case compression. The number of 2.5'' hard drives you can fit is largely determined by their thickness and how svelt of a right angle SATA adapter you can get. I did have to clip off a retaining hook on the main case panel but its right next to a screw point.
I got a lot of information here: parkytowers.me.uk
This probably works with most of the Z90 series but take a look inside and see.
HDD_Caddy_Wyse_Z90DW.stl | 670.9KB |