I finally ran into a situation where I wished the MacBook Air had a DVD drive or a FireWire port. I needed to restore from a SuperDuper backup on a disk image on an external drive to a vanilla MacBook Air and was a bit surprised that I didn’t know how best to do it. I called up Adam Tow and ran through a number of scenarios.

Basically it came down to this: I had to boot from a device that wasn’t the drive I wanted to copy to (the MacBook Air’s internal drive. That would allow me to overwrite the internal drive with my backup. I also needed the backup available when I’d booted up from the alternate startup device.

Here are the options I considered/tried:

1. Install from another computer using Air Disk. For some reason, I couldn’t join my Airport network from the Air after bootng up. As such, I moved on to other options.
2. Boot from USB stick that has SuperDuper on it, with both the USB stick and the backup drive hooked up via USB hub. I don’t have a USB drive with OS X on it and was concerned about the ability to make everything work from the USB hub, so I decided not to try this.
3. Install OS X on the external drive I was using for backups, then boot from the Air from that and clone back to the internal drive. This is ultimately what I decided to do.

I think #3 is the best option for several reasons. It’s faster than the Remote Disk option, and also is the same situation I’d have if I suffered a hard drive crash while traveling – which is what the external travel drive is really intended to guard against. I still ran into some issues with this approach.

I’d reformatted the external drive when I first got it, but I hadn’t reformatted it as a GUID partition. I had to copy the disk images with the SuperDuper backups to another computer/drive, reformat the external drive, install OS X and then copy them back again.

I wanted to install OS X on the external drive from the DVD that came with the Air, but when I tried to do that from my Mac Pro it complained about the machine not being compatible. Instead I installed from the DVD that came with the Mac Pro. This seemed to work.

Once I had installed OS X on the external drive and copied the disk image back to the external drive again, I tried to boot the Air from it. No go. It went into a loop where it would boot to a gray screen then reboot.

I realized that the external drive had 10.5.1 on it, which was before the Air was released. On a hunch I decided to see if upgrading the OS on the external drive would make a different. I plugged the drive back into my Mac Pro and updated the OS to 10.5.6. After doing this, I was able to boot the Air from the external drive. Yay!!

Once I had booted the Air successfully from the external drive, I then installed SuperDuper, mounted the disk image with my backup on it, and initiated a clone to the Air internal drive. I was so confident this would work that I set the post-copy action to “boot from Air internal drive”. I should have known better…

Once the clone from the backup to the internal drive was complete, the machine rebooted itself; again, and again, and again, and again… the same thing I’d seen before when booting from the external drive that had 10.5.1. I don’t know how long it did this before I went in to check if the clone was complete – I’m sure it was a totally good thing for the hardware.

At this point I was seriously considering wiping everything back to a basic install and copying over my apps, user dir, etc. However I was going to have the same struggle installing OS X again without a DVD drive or bootable installer on a USB stick, etc., so I decided to give it one more try.

Since I’d fixed this boot cycle issue once before by upgrading to 10.5.6, and the backup was 10.5.5, so I decided to try an upgrade. It’s not easy to upgrade a disk image though. I had to upgrade the original machine, then SuperDuper Smart Update the backup, then boot from the vanilla OS install on the external drive, mount the disk image, boot up SuperDuper, say a quick prayer to St. Steve and try Smart Update the Air internal drive from the updated backup disk image. Then I manually rebooted from the Air internal drive.

This worked.

Thank goodness.

So I guess this is a long-winded way of saying I really miss FireWire target disk mode. That’s a feature the Air, as a satellite device, should really support. It would have saved me an absurd amount of time in this process.