You cannot backup your entire hard drive to a disk image. Essentially there isn't enough space to do that nor is this the best method for doing a full disk backup. Full disk backups should be done to an external hard drive using proper backup software. You can clone your hard drive to an external drive using the Restore option of Disk Utility but DU cannot do incremental backups. For that you need backup software:
Basic Backup
Get an external Firewire drive at least equal in size to the internal hard drive and make (and maintain) a bootable clone/backup. You can make a bootable clone using the Restore option of Disk Utility. You can also make and maintain clones with good backup software. My personal recommendations are (order is not significant):
1.
Retrospect Desktop (Commercial - not yet universal binary)
2.
Synchronize! Pro X (Commercial)
3.
Synk (Backup, Standard, or Pro)
4.
Deja Vu (Shareware)
5.
PsynchX 2.1.1 and
RsyncX 2.1 (Freeware)
6.
Carbon Copy Cloner (Freeware - 3.0 is a Universal Binary)
7.
SuperDuper! (Commercial)
The following utilities can also be used for backup, but cannot create bootable clones:
1. Backup (requires a
.Mac account with Apple both to get the software and to use it.)
2.
Toast
3.
Impression
4.
arRSync
Apple's Backup is a full backup tool capable of also backing up across multiple media such as CD/DVD. However, it cannot create bootable backups. It is primarily an "archiving" utility as are the other two.
Impression and Toast are disk image based backups, only. Particularly useful if you need to backup to CD/DVD across multiple media.
Visit
The XLab FAQs and read the FAQs on maintenance, optimization, virus protection, and backup and restore. Also read
How to Back Up and Restore Your Files.
To clone with Disk Utility do the following:
How to Clone Using Restore Option of Disk Utility
1. Open Disk Utility from the Utilities folder.
2. Select the backup or destination volume from the left side list.
3. Click on the Erase tab in the DU main window. Set the format type to Mac OS Extended (journaled, if available) and click on the Erase button. This step can be skipped if the destination has already been freshly erased.
4. Click on the Restore tab in the DU main window.
5. Select the backup or destination volume from the left side list and drag it to the Destination entry field.
6. Select the startup or source volume from the left side list and drag it to the Source entry field.
7. Double-check you got it right, then click on the Restore button.
8. Select the destination drive on the Desktop and press COMMAND-I to open the Get Info window. At the bottom in the Ownership and Permissions section be sure the box labeled "Ignore Permissions on this Volume" is
unchecked. Verify the settings for Ownership and Permissions as follows: Owner=system with read/write; Group=admin with read/write; Other with read-only. If they are not correct then reset them.
For added precaution you can boot into
safe mode before doing the clone.