Keeping your snapshots and photos safe when you are out and about is as important as staying dry and warm on a cold and rainy day. After all, losing your photos, like going down with the flu, is no fun at all. If you already pack a laptop with you, you can use it to back up images from storage cards and cameras. But, lugging a full-blown machine just for this purpose is not very practical.

You can, of course, splurge on a dedicated storage device with a built-in card reader, but they tend to be rather expensive and limited. Instead of spending money on something like this, you can build your very own automatic backup device that can handle both cards and cameras and will cost only a fraction of what you would pay for a similar product on the market. All you need is a single-board computer (SBC) capable of running a regular Linux distribution and a dash of Bash scripting. Choosing the DIY approach will not only save you money, it will also allow you to build a much more versatile device and learn several useful techniques in the process.

It may come as no surprise that a Raspberry Pi makes a perfect platform for the mobile backup device: It's cheap and small, and it can run a Debian-based Linux distribution. Although any model will do, you might want to use the Raspberry Pi Model B for more flexibility, because it offers two or more USB ports. Instead of Raspberry Pi, you can use any other SBC that can run Linux. This project assumes that you are using Raspberry Pi 2 Model B running the latest release of Raspbian. The machine is connected to the local network and accessible via SSH.

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