Time Machine is the automatic backup program included with Mac OS X 10.5. With Time Machine, you no longer have to worry about backing up your data. You can set Time Machine to automatically back up all files and folders on your boot drive or just selected files and folders on any of your drives. Every hour, Time Machine will work in the background, saving new and changed files.

To start using Time Machine, open System Preferences and click the Time Machine button.

Time Machine preferences

Before activating Time Machine, you should select your backup drive and the files and folders to copy.

Backup Drive

The first time you connect an external drive to your computer, Mac OS X 10.5 will ask if you want to use that drive for Time Machine. You should only say yes if you want to back up your entire boot drive.

You can select a backup drive for Time Machine at any time by clicking the Select Disk... or Change Disk... button on the Time Machine preferences pane. A Finder pane will open and you can locate and select your backup drive.

Data to Backup

If you want Time Machine to back up all your files and folders, including system files, and you have only one drive attached to your computer, you are finished setting preferences for Time Machine and you can click the On button and close System Preferences. However, if you want Time Machine to back up only selected files and folders on any of your connected drives, click the Options... button on the Time Machine preferences pane. Another pane will open, asking you to add the drives, files and folders you do not want Time Machine to back up.

Time Machine options

To exclude drives, files and folders from Time Machine, click the plus symbol at the bottom of the pane and select all items you do not want backed up. If you change your mind about an added item, select the item in the pane and click the minus symbol under the list of items.

When Time Machine runs out of space on your backup drive, it will begin erasing old backups. To be warned before this happens, put a check in the box in front of Warn when old backups are deleted.

After you've set preferences for Time Machine, you need to activate it by switching the Off button on the Time Machine preferences pane to On. Once activated, Time Machine will do its first backup and then do incremental backups every hour.