When you create a differential backup, Image for Linux compares the condition of the source partition or hard drive to a full backup you identify to determine what changes have occurred on the source partition or hard drive since you created the full backup. A differential backup contains only the changed sectors. For details on differential backups, see Appendix B.
The process for creating a differential backup is very similar to the process for creating a full backup, and you set many of the same options during both processes. When you analyze the steps you take, you’ll notice the following differences:
* When you create a full backup, you identify the source drive you want to back up.
* When you create a differential backup, you identify the full backup Image for Linux should reference when creating the differential backup.
Insert your Image for Linux boot disk into the appropriate drive and boot your computer. On the Image for Linux Main Menu, select Backup. Then, follow these steps:
1. On the Backup screen that appears, select Changes Only.
2. On the Backup/Select screen that appears, select an option to determine how Image for Linux detects changes and performs the differential backup:
* If you choose Single Pass, Image for Linux identifies the changes you have made to the source partition since you created the full backup and then backs up those changes, all in one pass. You cannot use this option if the associated full backup spans multiple CD/DVD’s.
* If you choose Multi Pass, Image for Linux compares the source partition against the full backup in one pass and then makes the differential backup in a second pass. You must use this option if the associated full backup spans multiple CD/DVD’s.
3. On the Select Full Backup To Continue/Select File Access Method screen that appears, choose File (OS), File (Direct) or File (CD/DVD) to identify the location of the full backup related to this differential backup.
4. The appearance of the Select Full Backup To Continue screen that Image for Linux displays depends on the choice you made in Step 3.
* If you chose File (OS), a screen appears where you can select the full backup file name; see Step 5 for details.
* If you chose File (Direct), the Select Full Backup To Continue/Select File Drive screen appears; select the hard drive that contains the full backup from the list shown and then select the correct partition.
* If you chose File (CD/DVD), the Select Full Backup To Continue/Select Drive Interface screen appears. Select either ATAPI/SCSI or SG. Then, insert the first disc in the set and then select the corresponding CD/DVD drive from the list.
5. On the Select Full Backup To Continue screen that appears, select the .TBI
file that corresponds to the desired full backup. You can type the name of the
.TBI file (you don’t need to type the .TBI file extension) or you can press Tab and then use the arrow keys to highlight the file and press Enter to select it. If the .TBI file resides inside a folder, highlight the folder and press Enter to display the contents of the folder.
If you open a folder and want to navigate back to the parent folder, select the .. list item and press Enter.
If you select a file that you created using the encryption or the password-protect option, supply the correct password to continue.
6. On the Backup To/Select File Access Method screen that appears, choose File (OS), File (Direct) or File (CD/DVD) to identify the location where you want to save the differential backup files.
Note: You do not need to store files from a differential backup in the same location
where you store full backup files. When you restore a differential backup, Image for Linux will prompt you for locations for both the full backup files and the differential backup files.
7. The appearance of the screen that Image for Linux displays next depends on the choice you selected in Step 6. See Step 4 for a description of your choices. 8. On the Backup To screen that appears, supply a name for the differential
backup file(s). You do not have to supply a file extension—just the path and file name itself—Image for Linux will add the extension automatically. If you are using the File (OS) option, you must follow DOS naming conventions and use a file name that does not exceed eight characters. You might consider using today’s date in numeric form and include D as the final character to help you identify a differential backup. For example, if you are creating your backup on December 15, 2007, use 121507D as the file name.
9. On the Backup Options screen that appears, select the options you want to use. See the section, “Understanding Backup Options,” for an explanation of each option.
10. When you select Finish, the imaging process begins, and a progress bar appears on-screen. When Image for Linux finishes, a message appears to let you know that the backup was successful. You can interrupt the backup and validation operations at any time by pressing the F12 key. Image for Linux will ask you to confirm that you want to cancel before it interrupts the current operation.
After you press Enter to dismiss the message, the main menu for Image for Linux reappears. Select Exit and, when prompted, remove the Image for Linux boot disk and press Enter to reboot your computer.