Mac 101: Time Machine

Setting up Time Machine for backups

Setting up Time Machine is as easy as connecting an external hard drive to your Mac via FireWire or USB, or by connecting to a Time Capsule. You can also use a secondary internal disk if your desktop Mac has one i.e., a disk that you don't start up from.

Note: If you'll use Time Machine with a Time Capsule, skip to "Setting up Time Capsule for Time Machine backups" below.

When you connect a hard drive for the first time, Time Machine asks if you would like to use it as a back up drive (unless you've already specified a backup disk).

Click "Use as a Backup Disk" to confirm you want to use the disk for Time Machine backups.  Time Machine preferences will then open with this disk selected as your backup and Time machine turned on.

That's all you have to do for Time Machine to automatically back up your Mac.

Depending on the amount of data you have, your first back up may take a few hours to complete. You should not interrupt the initial backup. You can continue to use your Mac while Time Machine backs up. For more information, see "Backing up with Time Capsule for the first time".

Once the initial backup is completed, Time Machine performs subsequent hourly backups of only the files that have changed on your Mac since the last back up (as long as your backup disk is connected).

Time Machine keeps hourly backups for the past 24 hours, daily backups for the past month, and weekly back ups until your backup drive is full.

Note: If you use FileVault, your Home folder is backed up only when you are logged out.

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. See the documentation which came with your Time Capsule for information about setting Time Capsule up on your network.

Once your Time Capsule has been configured, open Time Machine preferences and click on the "Change Disk..." button. From the sheet that appears, select the Time Capsule. Enter the name and password you set for your Time Capsule. Time Machine preferences will then look like this:

Configuring Time Machine preferences

In Time Machine preferences (in System Preferences) you can click the Options button to adjust settings. A sheet similar to this appears when you click Options:

This sheet allows you to exclude files, folders, or entire volumes from being backed up. You might want to do this to avoid filling up your backup disk, for example.

Tip: If you regularly modify a very large file (greater than 1 GB, for example), you might want to add the file to the "Do not back up" list. Time Machine backs up modified files, regardless of how much or how little the file changed from the previous backup. 

The "Warn when old backups are deleted" option tells Time Machine warn you when older backups are removed from your backup disk to make space for more recent backups.
 

Restoring files from Time Machine backups

With Time Machine you can go "back in time" to restore files or your entire system. Make sure your backup disk is connected and mounted (if not, Time Machine will alert you that "The storage location for Time Machine backups can't be found" when you open Time Machine).

Restoring specific files or folders

While your backup disk is connected, 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".

You can use the timeline on the right side of the window to reach a certain point back in time (the timeline shows the times of all backups on your backup disk). If you don’t know exactly when you lost a file, you can use the back arrow to let Time Machine automatically travel through time to show you when that folder last changed.

You can also perform a Spotlight search in the Finder to find a file. Simply type the Spotlight search field and use the back arrow to have Time Machine search through your backups to find what you are looking for.

Before you restore a file, you can also use Quick Look to preview a file to make sure its the one you want. Highlight the file and press the Space Bar to bring up a preview.

To restore, select the file/folder and click the "Restore" button. The file will automatically be copied to the desktop or appropriate folder.

Note: If you use FileVault, you cannot browse for individual items in your Home folder. However, you can restore all files and folders by using the Restore System from Backup feature of the Mac OS X Installer.
 

Restoring all files or a FileVault-protected Home folder

With your backup disk connected, start from your Mac OS X 10.5 installation disc. After starting up, use the Restore System from Backup feature of the Mac OS X Installer.
 

Using an existing Time Machine backup with a new Mac

If you buy a new Mac you can transfer all of your applications, files, settings, and other ifnormation from your existing Time Machine backup. This can be done when you start up your Mac for the first time or by using the Migration Assistant application, located in the Utilities folder, in the Applications folder.

To do this via a Time Capsule, see this article.