Timemachine Disk has become read-only - possible to repair using Testdisk?

[atjb]

Hi all,

I have a disk that is used only for timemachine connected by USB.

Everything seemed fine and I shut my computer down as normal one evening, but on powering up again I got this error:



I tried to run first aid in Disk Utility as a first fix, and got the following errors:



I tried to follow step 7.9 of the FAQ, but testdisk showed that both file headers were OK.



Are there any other suggestions? I can read the disk fine, but I can't add new backups to it. I know that trying to copy a timemachine backup to another disk will make it take up exponentially more diskspace than the current size-on-disk, because it will make a new copy of each file rather than just a link. I don't have any software to perform a byte-by-byte clone.

At the moment I'm thinking of just reformatting the disk and restarting my TimeMachine backup - I don't think I'll lose anything if I do it now.

[recuperation]

I don't have any software to perform a byte-by-byte clone.

Use a live linux like GParted (very small file to download) and use ddrescue as described in the manual file Testdisk.pdf

For further information how to interpret the line "invalid key length" please consult with a specialized apple forum.

[atjb]

Thanks for your replies.

From reading around performing a clone of the drive while ignoring the hardlinks that Apple uses to make timemachine possible would also clone the corrupted file system. I decided to simply start afresh on the Timemachine backup. If the problem happens again I'll need to look at replacing the drive.

Cheers!