With OS X Lion out, a lot of people will take advantage of the weekend to upgrade their Macs to the new operating system. But before running the upgrade, you should do the single most important thing to protect your files: back them up. Ideally, you should back up your entire startup disk, “cloning” it, making a full copy that you can boot from if you have any problems. To do this, you need an external hard disk, but you can get a good-sized one for around $100. And this is a device you should own, to back up your files regularly.<\/p>\n
If you don’t have an external hard disk, you can back up your important files – those in your home folder – to DVDs, but it takes a bit longer. You can also back up to a network volume, if you have other computers on a network, or to an online server.<\/p>\n