A network storage device is one of the best ways to keep your data backed up, but it can be pricey to set up, and leaving a computer on all the time sucks a lot of power. If you're looking for a cheap and low-power solution, How-To Geek shows off how to use a Raspberry Pi with a external hard drive as a NAS.
The process of using a Raspberry Pi as a NAS is straightforward, and the only additional equipment you need is a USB hard drive (or two for redundancy). First off, you need to do the initial setup process for the Raspberry Pi. Then you need to run a few commands to get the external hard drive working on the network and set up your PC to send the data over.
The end result is a NAS that uses very little power compared to a traditional computer running all the time. If you need something with a little more power, that can be easily done too. Head over to How-To Geek for the full guide to putting this together for yourself.