In the Applications directory, there is a subdirectory called Utilities. In Utilities you'll find Migration Assistant. Or just use spotlight to launch it.
Migration Assistant has the option to restore from another machine, a Time Machine Backup, or another disk.
Make sure the TM disk is plugged in to your wife's new machine, and you should be able to select it from a list of volumes.
Can I copy those .sparsebundle files to an external hard disk and expect them to work as Time Machine backup resources again?
Almost certainly yes.
Modes and ownership
Ideally, use chmod(1) and chown(8) to have the mode and ownership, of the copy of the disk image, consistent with how Mountain Lion normally creates a local disk image for Time Machine.
Example
GPES3E-gjp4-1:~ gjp22$ sudo ls -al /Volumes/tall/com.apple.backupd/GPES3E-gjp4-1.sparsebundle/
Password:
total 16672
drwx------@ 3 root staff 10 7 Jun 19:07 .
drwxr-xr-x 8 gjp22 staff 10 6 Jun 18:57 ..
-rw-r--r-- 1 root staff 500 7 Jun 18:03 Info.bckup
-rw-r--r-- 1 root staff 500 7 Jun 18:03 Info.plist
drwx------ 2 root staff 78855 7 Jun 19:07 bands
-rw-r--r-- 1 root staff 444 7 Jun 18:02 com.apple.TimeMachine.MachineID.bckup
-rw-r--r-- 1 root staff 444 7 Jun 18:02 com.apple.TimeMachine.MachineID.plist
-rw-r--r-- 1 root staff 1473 6 Jun 21:28 com.apple.TimeMachine.Results.plist
-rw-r--r-- 1 root staff 10698 6 Jun 22:24 com.apple.TimeMachine.SnapshotHistory.plist
-rwx------ 1 root staff 0 19 Mar 19:36 token
– and for each band, you should have:
-rw------- 1 root staff
Attaching the copy of the disk image
With Terminal, for the example above:
sudo hdiutil attach -readonly /Volumes/tall/com.apple.backupd/GPES3E-gjp4-1.sparsebundle/
If you use Terminal from within Recovery OS: you'll probably not need the sudo prefix to the command.
Additional detail
… whether I can still restore …
You require:
- a copy of a Time Machine destination, a copy that will be good for restoration
- not an additional Time Machine destination.
Assumption
You wish the copy to be usable, for restoration only, in the event of loss or failure of the Time Capsule.
If the disk is attached from a local image where modes and ownership vary from the norm for a local image:
- OS X or Recovery OS might use that disk without difficulty; I can't be certain.
Thoughts
If you're preparing for the possibility of loss or failure of a Time Capsule – and restoration from a copy of what was there – then think a step further, to backing up without the original Time Capsule. (If you wish the copy to be writeable by Time Machine, that could be a separate question.)
All things considered
It's probably quicker and simpler to use the external hard disk, or a part, as a Time Machine destination.
Best Answer
I found a solution that does use the existing backup. The trick is to use
sudo tmutil associatedisk(seeman tmutil).My old disk was mounted under
/Volumes/USB-oldand the new disk is mounted as/Volumes/USB-new. My backup is under/Volumes/backups. (If your old and new disk have both the same name, you have to follow all of the steps, because the name of the disk is not sufficient to associate an old backup with a new disk)Restore the old data to the new disk:
(note this does not restore files starting with
.at the top level)Tell time machine to associate the new disk to the old backups:
Start time machine to do backups
Now time machine does not try to backup the entire new disk. Instead, it creates incremental backups based on the old snapshot.
However, it seems not possible to go back in history using Time Machine. I have tried to associate all old backups with the new disk without much success: