You may wish to store the external disk in a different location (an offsite backup). If your external disk does not have enough free space to hold future backups, consider using a different disk or deleting prior backups to free up space on the external disk.
Instructions for backing up to an external hard disk via Disk Utility
- Connect an external hard drive (FireWire or USB) that has sufficient free space to hold at least one copy of the contents of your Macintosh HD.
- Start from your Mac OS X 10.5 or 10.6 Install DVD. (Insert the disc, then restart and hold the C key.)
- Select your language. DoÂ not start an installation.
- Choose Disk Utility from theÂ Utilities menu.
- Select the disk you wish to back up (your source disk, such as Macintosh HD) in the source pane on the left.
- Click “Verify Disk” to check the hard disk for issues. If an issue is found, click “Repair Disk” to repair.
- Click the “New Image” button in the toolbar.
- Give your image a useful name such as “04-15-2009 Macintosh HD backup”. A date in the name makes it easy to tell when the backup was made.
Note: For additional security, you can encrypt the backup disk image. From the “Encryption:” pop-up menu, select either 128-bit or 256-bit AES encryption. When prompted enter a password for the encryption: Use the password assistant to help you make a good password.
- Be sure the Save destination is a location on yourÂ external hard disk, then click “Save” to continue.
- Enter your admin name and password if prompted. The imaging process will begin. The time it takes to complete the imaging process depends on factors such as the amount of data on your Macintosh HD. Approximately 1 GB per minute will be imaged, depending on various factors.
- When the imaging process is complete, select the newly created disk image in the device pane. Â Then, chooseImages > Scan Image for Restore... from the menu bar, and let the scan complete.
- Quit Disk Utility (press Command-Q). Then press Command-Q to quit the Mac OS X installer; you will be prompted to restart.