Restoring Your Entire System / Time Machine

Q: Can I restore my Macs’ entire system, and how is Time Machine involved?
A: Yes, you have several options, each involving increasing degrees of severity. In all cases Mac OS 10.5 (Leopard) will be required as previous OS X versions do not work with Time Machine backups. Naturally, all of these methods will require a significant amount of time, so plan accordingly.
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*Archive & Install*
An Archive and Install is the least invasive of the 3 methods. This approach results in a fresh copy of the Mac OS system software while at the same time preserving all current user accounts on your Mac. Additionally, this method will permit Time Machine to continue backing up to the same set of backups it did prior to the installation.

Procedure:
Verify that your Mac has uninterrupted AC power.
Turn “OFF” Time Machine in the Preferences.
Insert your original Mac OS 10.5 Leopard DVD and reboot while holding down the “C” key.
At the “Welcome” screen click “Continue”.
At “Select a Destination” choose your Macs’ hard disk.
Click “Options” in the lower left.
Choose “Archive and Install”.
Ensure that “Preserve Users and Network Settings” is checked.
Click “OK”.
Back at the “Select a Destination” screen click “Continue”.
At “Install Summary” click “Install”.

Once the installation is complete, use Software Update to bring your Mac up to date.
Next, Launch Disk Utility, select your Macs’ internal disk on the left, and click “Repair Disk Permissions”.

During this initial period, Spotlight is going to re-index your Mac’ hard disk. This can take up to several of hours depending upon the volume of data. Allow it to complete before resuming Time Machine backups. You can monitor its’ progress by clicking on the Spotlight icon in the menu bar.

During the installation a new folder was created at the root level of your hard disk labeled “Previous Systems”. These are all the system files that were just replaced with fresh copies. If you are comfortable, you can delete this folder right away. Otherwise, wait a week or so incase there is something you wish to retrieve, then delete it.

Finally, turn Time Machine back “ON” in the Preferences. Time Machine should continue to backup to the same set of backups that it did prior to the Archive & Install. However, due to the extensive changes to the systems’ directories, the first backup will require a lengthy session of “Preparing...” as Time Machine performs a “deep traversal”. Allow this to proceed uninterrupted. Naturally, this first backup may be a significant one, perhaps involving several GB of data, so attempting this wirelessly will require time and patience.
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*”Restore System From Backup...”*
If however, your system has experienced a serious malfunction, or a Mac OS software update has produced undesirable behavior, you can perform a full system restore from your Time Machine backups. This will result in a system virtually identical to the OS environment that existed on the date of the backup you choose to restore from. All system software, applications, and user accounts will be replaced with copies as they existed when that backup took place. The advantage here is that, generally, no further installation of 3rd-party software is required and all of your personal & system settings a preserved. The disadvantage is that because you retain your personal settings and system files, you run the risk of reintroducing any problems you experienced with the previous installation, including issues that necessitated the full restore in the first place.

Naturally, the time and date you choose to restore from can make a significant difference in the state of your resulting OS environment. Choosing the most recent date from which to restore is most desirable. If, however, one or more Time Machine backups occurred after you began experiencing issues with your system, then going farther back in time to restore from will be more advantageous. Files created or modified after you began experiencing system issues may later be recovered via Time Machines’ “time travel” interface (“Browse other Time Machine disk...”).

Unfortunately, restoring your system by this means will result in Time Machine abandoning previous backup sets and beginning a new set. So verify ahead of time that you have enough space on your backup drive for another full backup. Alternatively, once the full restore is complete, you can delete the old backups to free space on the drive. Or you can begin backups on a different hard disk while retaining the older backups until you are satisfied that the current set have accumulated enough history.

Procedure:
Verify that your Mac has uninterrupted AC power.
For faster installation, Time Capsule/AirDisk users should connect their Macs directly to their Airport device via ethernet.
Insert your original Mac OS 10.5 Leopard DVD and reboot while holding down the “C” key.
At the “Welcome” screen go up to the “Utilities” menu and select “Restore System From Backup…”.
The “Restore Your System” window reminds you that this procedure will erase all data on your Macs internal hard disk. Click “Continue”.
At “Select a Backup Source” choose your Time Machine backup disk and click “Continue”. (If the backup disk you are restoring from is a network drive then click “Connect to Remote Disk”. Next, choose the disk image from which the restore will be drawn from and click “Continue”.)
At “Select a Backup” choose from which set of backups you would like to “Restore From” in the drop-down menu. (If your backup drive only has one set, this will be grayed out.)
Next, highlight the date and Mac OS X version from which you would like to restore.
Click “Continue”.
At “Select a Destination” choose your Macs’ internal hard disk. Give the installer time while it calculates the space required for the restore. When ready click “Restore”.
Confirm your desire to erase the drive by clicking “Continue”.

Obviously, this will take quite some time. But when the installer finally announces it has finish, click “Restart”.

After logging in, immediately go to System Preferences --> Time Machine, and turn “OFF” backups, even if a backup attempted has begun.
Next, Launch Disk Utility, select your Macs’ internal disk on the left, and click “Repair Disk Permissions”.

During this initial period, Spotlight is going to re-index your Mac’ hard disk. This can take up to several of hours depending upon the volume of data. Allow it to complete before resuming Time Machine backups. You can monitor its’ progress by clicking on the Spotlight icon in the menu bar.

Finally, turn Time Machine back “ON” in the Preferences. Time Machine should continue to backup to the same set of backups that it did prior to the restore. However, due to event logs being out of sync, the first backup will require a lengthy session of “Preparing...” as Time Machine performs a “deep traversal”. Allow this to proceed uninterrupted. Additionally, the subsequent backup may be quite substantial involving many GB of data, but don’t be alarmed.

Your system has now been restored to virtually the same state it was in on the date of the backup you chose. (See this article for a list of files that TM does not restore, http://shiftedbits.org/2007/10/31/time-machine-exclusions/)
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*Erase, Install, & Migrate*
A final option, reserved for last resort, is to erase the hard disk, install a fresh copy of the Mac OS, and then use Migration Assistant during the installation to restore your user accounts. This is the Mac equivalent of ‘Slash and Burn’, and really should only be necessary if you require a completely fresh start.

Procedure:
Verify that your Mac has uninterrupted AC power.
For faster migration of user data, Time Capsule/AirDisk users should connect their Macs directly to their Airport device via ethernet.
Insert your original Mac OS 10.5 Leopard DVD and reboot while holding down the “C” key.
At the “Welcome” screen click “Continue”.
Click “Agree” to the user agreement.
Select you Macs internal hard disk and click “Options”.
Select “Erase and Install”.
Select “Mac OS Extended (Journaled)” for disk format. (Avoid selecting “Case-sensitive” unless you know what you are doing.)
Click “OK”.
Click “Continue”.
At “Install Summary” click “Customize” if you would like to eliminate certain Print Drivers, Fonts, or Language packages from being installed. Otherwise, click “Install”.
If you wish, you can click “Skip” when the DVD integrity check begins.

After the initial installation completes, your Mac will restart and you will see the video introduction.
At “Welcome” select your country and then preferred keyboard.
At “Do You Already Own a Mac?” you are asked “Would you like to transfer your information?”

+from another Mac+
+from another volume on this Mac+
+from a Time Machine backup+
+Do not transfer my information now+

Select “from a Time Machine backup” and click “Continue”.
At “Select a Backup Volume” choose your Time Machine backup disk and click “Continue”. (If you are attempting the migration wirelessly, then click “Join...” and select your network first.)
At “Transfer Your Information” check all the categories you wish to migrate over. If you wish your Mac to be in the same state as your last backup, then check everything. Give the installer time to calculate sizes.
Once that is complete, the “Transfer” button will become active and you can click it.

After the install, verify the registration information, click “Connect” and you are done.

After logging in, immediately go to System Preferences --> Time Machine, and turn “OFF” backups, even if a backup attempted has begun.
Next, Launch Disk Utility, select your Macs’ internal disk on the left, and click “Repair Disk Permissions”.

Interestingly, no Spotlight indexing appears necessary, so, once the permission repair is complete, turn Time Machine back “ON” in the Preferences. Time Machine should continue to backup to the same set of backups that it did prior to the restore. However, due to event logs being out of sync, the first backup will require a lengthy session of “Preparing...” as Time Machine performs a “deep traversal”. Allow this to proceed uninterrupted. Naturally, the first backup after a significant installation like this will be quite large so don’t be alarmed.