One of the most anticipated features in Mac OS X 10.5 Leopard is Time Machine. Dubbed "backups for the rest of us," Time Machine is truly a revolutionary approach to backups. Although its sci-fi, 3D interface is the first thing you notice, Time Machine has a lot going on under the hood that makes it unique and powerful.
For one thing, Time Machine is amazingly fast because it doesn't have to scan the file system for changes since the last backup (as most conventional tools do). Because Leopard allows the file system to track the changes made as files are updated, Time Machine can simply query the file system for that information, which speeds up the backup process enormously.
While this performance boost is a great advantage, Time Machine really shines in its ease of use. There is virtually no configuration or maintenance needed to use Time Machine. Simply select a place to store your backups and Time Machine will do everything else (set a schedule, back up files, and even remove outdated backups).
Choosing a Hard Drive
The first time that an external hard drive is connected to your Mac after Leopard has been installed, you'll see a dialog asking if you want to use that hard drive with Time Machine to store backups. If you say yes, then that's all the configuration that you need to do. Time Machine will begin backing up your computer using the attached hard drive.
The initial backup can take a while because all the data on your computer (both on your startup disk and other hard drives attached to your computer) is copied. Apple suggests that you setup Time Machine and then let it perform the initial backup overnight. Subsequent backups occur automatically and are often significantly faster.
You can also choose a backup drive in the Time Machine pane of System Preferences (see figure 1). You can choose any internal or external hard drive. External or network drives are generally better choices because they are less likely to be affected by a hardware failure of your computer. If you are using a partitioned drive, you have the option of choosing any partition.
Figure 1. The Time Machine preferences
Typically, you will want to leave Time Machine running all the time to be certain that everything is backed up on a regular basis. If you want to disable Time Machine, however, you can do so using the on/off switch in the Time Machine preference pane. You can also change the disk you back up to at any time using the Change Disk button (though you will have to wait for Time Machine to perform a new initial backup).