Imagine that just as you're reading this your computer screen goes blank and nothing you do will bring it back to life. You call someone in and they explain that your hard disk has died and all the information on it is lost. How much of a disaster would that be?
Computers are complex machines and sometimes they break down. No matter how carefully you treat them at some point something inside them will go wrong and that will be that. If it's the hard disk that breaks then all of the information on your computer will be gone - the files, documents, programs, settings, pictures, music, everything. It's at this point that you need a backup.
There are many ways of backing up your computer data but using an external hard disk is the
simplest and cheapest solution for most people. If you have exceptional needs - very quick recovery
time or off-site storage for example - you should probably get some expert advice.
(As memory stick prices have dropped it's become possible to use them for
regular backups if you're just backing up your user data. Contact me for more details.)
When you make a backup of your computer's data it's not a case of putting it in a 'safe place' - an external hard disk is just as likely to break as the hard disk in your computer. The security comes from having the data in two places, either of them might fail but the odds of both of them breaking at the same time are low enough to be negligible.
There are two ways of backing up your data, the one you will use depends on the version of Mac OS X that is running on your computer. Click on About This Mac from the Apple menu (at the top left of your screen) to find out - if you're using 10.5 (Leopard), 10.6 (Snow Leopard) or later you can use Time Machine which will already be on your computer, if you're using 10.4 (Tiger) you can use Silverkeeper which you'll need to download and install. If you're using an earlier version contact me for more advice.
Both backup programs are fairly straightforward to set up and run but if you have any problems or questions (or just don't want to have to learn about them) then contact me. There are a couple of things that can help make the backup process easier and more reliable:
Time Machine
A Time Machine backup includes everything on your hard disk. If you have large files that you don't need backing up (movies or other video files for example) you can tell the system to ignore them. Select System Preferences from the Apple menu, click on the Time Machine button then click on the Options button and add the folders that hold unwanted files.
Silverkeeper
Silverkeeper is a free backup program made by LaCie, you can download it from www.lacie.com/silverkeeper/. You'll need to give a name and email address to register for it but they won't send you spam so long as you remember to untick the mailing list boxes just above the Download button. Drag the Silverkeeper program icon into your Applications folder once you've downloaded it.
Silverkeeper is slower than Time Machine so I usually advise people to just back up their user folder. This means you won't be able to restore any applications (programs) that you don't have the install disks for. Make sure you take care of your disks!
If you delete a file from your computer Silverkeeper will also delete it from the backup. If you want to keep deleted files (in case you delete one by accident) you need to change this setting in the program options.
Buying and setting up an external hard disk
Any external hard disk can be used for backups but I usually recommend a 'mobile' model - they have an extra level of anti-shock protection and don't require a power supply. I currently use a Freecom Toughdrive which has a very convenient built-in cable (if you have a laptop - the cable is very short). For desktop computers that will stay in one place an ordinary external hard drive is fine and will be faster and cheaper.