Mac OS X v10.5, v10.6: How to back up and restore your files

Summary

Learn how to back up and restore your files in Mac OS X v10.5 or later.

Products Affected

Mac OS X 10.6, Mac OS X 10.5, MobileMe iDisk

You should perform regular backups of your system and keep multiple backups of important, irreplaceable files. Without multiple backup copies of your files, your files do not exist anywhere except on your Mac.
Tip: You should also keep at least one backup copy of your important files in a different physical location (that is, an "offsite" location). An easy backup method is to copy important files to a MobileMe iDisk, or via iWork.com for iWork '09 documents.
Using Time Machine
Mac OS X v10.5 and later include Time Machine so you can automatically back up your system and your important, irreplaceable files to a different hard disk or network volume. Time Machine also has an intuitive interface for restoring your files or your entire system.
See this article for more information about Time Machine.

Using Disk Utility
This alternative backup process will produce a disk image of your entire Mac OS X disk's contents. This process preserves the unique attributes of your files, such as permissions, ACLs and UUIDs. A disk image backup is good for an archive-type backup for offsite storage.
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

1. 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.
2. Start from your Mac OS X 10.5 or 10.6 Install DVD. (Insert the disc, then restart and hold the C key.)
3. Select your language. Do not start an installation.
4. Choose Disk Utility from the Utilities menu.
5. Select the disk you wish to back up (your source disk, such as Macintosh HD) in the source pane on the left.
6. Click "Verify Disk" to check the hard disk for issues. If an issue is found, click "Repair Disk" to repair.
7. Click the "New Image" button in the toolbar.
8. 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, or see this link for information about how to choose a good password.
    
9. Be sure the Save destination is a location on your external hard disk, then click "Save" to continue.
10. 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.
11. When the imaging process is complete, select the newly created disk image in the device pane.  Then, choose Images > Scan Image for Restore... from the menu bar, and let the scan complete.
12. Quit Disk Utility (press Command-Q). Then press Command-Q to quit the Mac OS X installer; you will be prompted to restart.

Restoring the backup disk image's contents to your internal Mac OS X disk

Note: If the Mac you are restoring to is not the same Mac you used to make the backup disk image, use Migration Assistant instead of Disk Utility to properly transfer the data back to your Mac.
Important: These steps will overwrite data with the same name in the same location, such as files on your desktop and in your Home folder.

1. Connect the external disk you've backed up to.
2. Start from your Mac OS X 10.5 or 10.6 Install DVD. (Insert the disc, then restart and hold the C key.)
3. Select your language. Do not start an installation.
4. Choose Disk Utility from the Utilities menu.
5. Select your internal Mac OS X disk that you want to restore to.
6. Click the Restore tab.
7. Drag your internal disk to the "Destination:" field.
8. Click the "Image..." button next to the "Source:" field.
9. Navigate to the location of the backup image you want to restore (located on your external disk).
10. Click "Open" to continue.
11. Click the "Restore" button. Confirm you want to "Restore to Disk" by clicking "Restore" again. This will replace data on your Mac OS X volume with data from your backup that has the same name and is in the same location.
12. Enter your admin name and password when prompted. If the backup disk image is encrypted, enter the disk image password if necessary. The time it takes to restore from the image depends on factors such as the amount of data on your backup disk image.

Using iDisk and iWork.com to back up important files
As a MobileMe or iWork.com subscriber, you can back up files to your MobileMe iDisk or use iWork.com (for iWork '09 files) via the Internet.
These services can be considered "offsite backups" for important files. To restore files, access MobileMe or iWork.com via the Internet from any Mac OS X 10.5-based Mac.

Click here to learn about using the MobileMe Backup application for important files

Manually backing up files
You can also manually drag files from your Mac OS X volume to an external storage device or network volume. You can also burn backup copies to blank CDs or DVDs in the Finder. Usually, your Home folder is where your most important files to back up are. Mac OS X and third-party applications can be reinstalled from original discs or source image files if necessary.

Additional Information

Using an IMAP email service such as MobileMe is a good way to make sure you have an offsite server copy of your email. For more information about IMAP email service, see Choosing POP or IMAP for your MobileMe email.
If you want to verify the integrity of your backups, use Disk Utility to check the backup disk images:

1. In Disk Utility, choose Images > Verify...
2. Navigate to the location of your backup disk image.
3. Click the disk image you want to check.
4. Click "Verify" to perform an image verification.