Time machine usage for backups under Snow Leopard

Snow Leopard operating system’s Time Machine feature allows you to automatically back up your entire system. It keeps an up-to-date copy of everything on your Mac, and enables you to easily go back in time to recover files.

You’ll now learn how to set up Time Machine to perform backups, restore items (or your entire system) from a backup, and use existing backups on a new Mac.

Setting up Time Machine for backups

Setting up Time Machine is as simple as connecting an external hard drive to your Mac, or connecting to a Time Capsule.

The Apple Time Capsule is a wireless network-attached storage device, combined with a wireless residential gateway router. It is designed to work in tandem with Time Machine. If your Mac has a secondary internal disk (specifically, a disk that you don’t boot up from), you can use Time Machine with that as well.

1. If you’re connecting a hard drive for the first time, Time Machine asks if you’d like to use it as a backup drive (provided you haven’t already specified a disk for this purpose).

2. Press the Use as Backup Disk button to confirm that you want to use the disk for Time Machine backups.

Time Machine preferences allow you to select a backup disk and schedule.

3. Time Machine preferences open with this disk selected as your backup and Time Machine activated. Depending on how much data you have, your first backup may take up to a few hours to complete. You shouldn’t interrupt the initial backup, but you can continue to use your Mac while Time Machine is working.

4. After your initial backup is completed, Time Machine runs hourly backups of just the files that have changed on your Mac since the last backup (provided your backup disk is connected).

5. Time Machine stores hourly backups for 24. hours, daily backups for a month, and weekly backups until your backup drive is full.

Setting up Time Capsule for Time Machine backups

If you have a Time Capsule on your network, you can use it as a Time Machine backup disk.

1. Once your Time Capsule has been connected, open Time Machine preferences (in System Preferences) and press the Change Disk button.

2. In the window that appears, select the Time Capsule.

3. Enter the name and password you set for your Time Capsule.

Configuring Time Machine preferences

In Time Machine preferences (in System Preferences), you can press the Options button to adjust settings.

1. This window allows you to exclude files, folders, or mounted volumes from your backup schedule. This is useful when you want to avoid filling up your backup disk.

2. Selecting the Warn when old backups are deleted option lets you know when older backups are deleted from your backup disk to make space for more current backups.

Restoring files from Time Machine backups

Time Machine enables you to go back in time to restore files, or your entire system. To restore files, make sure your backup disk is connected and mounted. If it’s not, Time Machine alerts you that the storage location for Time Machine backups can’t be found when you open it.

1. Click the Time Machine icon in the Dock, and the Time Machine interface appears. You can literally see your windows as they appeared back in time.

2. Use the timeline, on the right side of the window, to reach a certain point in time. If you’re not sure exactly when you lost a file, you can use the back arrow to let Time Machine automatically show you when that file last changed.

3. You can perform a Spotlight search in the Finder to locate a file. Type into the Spotlight search field, located in the upper right corner of the screen, and use the back arrow to have Time Machine search through your backups to find the desired item.

4. Before you restore a file, you can also use Quick Look to preview the file to make sure it’s the one you want. Highlight the file and press the spacebar to bring up a preview. Using Quick Look allows you to preview a file before restoring it.

6. To restore, select the file or folder and press the Restore button. The file is automatically copied to the Desktop or appropriate folder.

You can restore all files and folders by using the Restore System from Backup feature of the Mac OS X Installer.

Using an existing Time Machine backup with a new Mac

If you’ve used Time Machine to back up your Mac, you can transfer your applications, files, and settings in their entirety from an existing backup to a new Mac. This can be done either when you start up your new Mac for the first time, or by using the Migration Assistant application, located in Applications > Utilities.

Deleting old backups

When your backup disk begins to reach its capacity, Time Machine smartly deletes the oldest backups to make room for newer ones.

If your backup disk fills up often, causing your oldest backups to not go as far back as you want, consider the following options:

• Specify a larger disk for your backups. Use Time Machine preferences to select the disk when you connect it for the first time.
• Add to the “Do not back up” list in Time Machine preferences to reduce the amount of information being backed up.
• Delete files that are no longer needed so that they will no longer be backed up.
• Use Time Machine to find files that can be removed from the backup disk to conserve space.