Hello readers. I know at least a few of you who read this blog have Macs. This post is for you.

If you don’t have an external hard drive for backing up your Mac, get one. Now.

Especially if your Mac is more than three years old. Your computer is on borrowed time. It will eventually crash. I could go into all the technical details of why and how your hard drive could eventually die, but the odds are against you.

So here’s what you do. Find the size of your drive and then go out and buy the cheapest external USB drive you can find.

Step one: find the size of your Mac’s hard drive.

  1. Click once on Macintosh HD to select it (or whatever your drive is named).

  2. Press [Apple] + [i] or go to File > Get Info

  3. See where it says capacity? Buy an external drive that’s at least that big. 1.5 x the size is a good reference.

E.g. If you have a 40GB hard drive, you can’t get a 60GB hard drive anymore. They don’t make them. They’re old and small. So just find the smallest drive you can, perhaps a 160GB or 250GB. Just make it cheap. It can be any drive, it doesn’t have to say Mac-compatible. They all are.

Step two: back up your computer.

Apple makes this really easy.

  1. Plug in the drive.

That’s it. When your computer asks if you want to use this for a Time Machine backup, you say yes. All done.

If for some reason it doesn’t prompt you, then just go to System Preferences, click on Time Machine, and figure it out. It’s easy.

I cannot emphasize enough the importance of backing up your computer. Be patient: the first backup will take a while. You’ll probably have to let it run overnight. If you’re on a laptop set the Energy Saver preferences so it doesn’t go to sleep. Then after the initial backup, you’ll want to leave your computer on and the external drive plugged in every once in a while, especially after just downloading pictures or music, or doing lots of hard work on a document or resume or thesis or what-have-you.

Having a backup of your computer is easy and it’s very very important. I did computer repairs for many years (and still do) and I cannot emphasize this enough. I care about you, and you should care about your data. So please, buy a cheap drive and back up all the priceless stuff you have on your computer: the photos, the videos, the music, the papers you wrote, the spreadsheets. Everything.

This is the last time I’m going to bring this up. Let’s hope you never have to use your backup drive. But if you do, it’ll be there for you: a cheap insurance policy for invaluable data.

P.S. There’s another option for a networked drive so you don’t even have to plug it in, it just has to be on the same network. Apple calls it the Time Capsule. They’re cool but a little more expensive.