I have a Macbook for which I wanted to make a backup in case something ever happened to the drive.

I took the drive out of the macbook and made an exact clone of the drive using ddrescue to a brand new drive of the same size.

I tried putting the cloned drive into the macbook and it wouldn't recognise it. I hooked it up to a windows computer (which has software installed to read HFS+ volumes), and it said the volume was not allocated in Disk Management. When I connect the original drive it can see the partitions in Disk Management no problem.

When I scanned the drive using data recovery software, it picks up the partitions just fine so I know the clone worked.

Is there any reason why a perfect clone would behave differently in this situation? The original is a HGST and the new drive was a Western Digital, but both exact same number of LBAs. Could the fact they are different brands be causing an issue?

Cheers for any advice

Hi Taserx! You can try opening the first sector of both drives with an hex editor and check if they are exactly the same.

Best,

F.

Ok I'll give that a go. But ddrescue reported 0 errors so I don't understand how they could be different if they are.

Me neither , but i think it is a good way to start figuring it out.

Best!

F