Low Power File Server for a Sailboat

Posted: April 6th, 2017 | Author: | Filed under: Linux, Work | No Comments »

mason_43_photoRecently I was lucky enough to be a crew member on a sailboat that was making passage through the Caribbean. The Captain of the vessel, who lived aboard, was speaking to me about data storage and how difficult of an equation it was. Sailboats have very little power available to them when they’re underway as most don’t run their engine which is the only source to power the limited batteries kept onboard. He was thinking about picking up a Drobo-Mini and using SSDs to reduce the amount of draw on his system, however this solution is DAS based and doesn’t allow him access to the data unless he plugs directly into the box which means, you need a computer as well. Which is even more draw on the electrical system.

After a quick think and a look around the Internet I decided that the best way to address this issue would be to use a Raspberry Pi 3, a four port USB hub,  multi-SD card reader, and mdadm, with smb, nfs, and upnp. I’m not going to go into the nitty gritty of how to setup a raspberry pi as there are many tutorials available online already. However I will touch on some performance metrics that I was able to pull.

It’ll be small physically, have very little power draw, each microSD card draws between 66–330 mW during data transfer, at idle 0.2mA. Each bank will be less than 1mA at idle and 1.2W during transfer. Each bank should yield close to 800GB, all together I’ve calculated 3.2TB of data storage at 6-8W. Pretty dope hey?
The issue is cost. Prices in CAD
Computation
Raspberry Pi is $60
case and parts $20
USB Hub $26
total: $106 plus tax / shipping
Data Storage
Four card reader $20
200GB microSD card $91
800GB bank total $384 plus tax / shipping
Performance
Performance will max out at around 40MB/sec which isn’t great however we’re not looking for performance we’re looking for efficiency.
I welcome comments to this plan below :) My next step to this plan would be to get the Pi to be a wireless access point as well.