I backed up a hard drive in a dmg, then reformatted the hard drive. (I had deleted the efi partition before which was preventing me from reinstalling the operation system). When I tried use the restore function in disk utility it gave an input/output error. I get this error with anything I do to the image including mounting, converting, attaching, verifying, scanning, and getting info through hdiutil imageinfo.

I have run all of these with hdiutil and the -noverify, -nomount, and -ignorebadchecksums flags. When I copy the image onto another disk/partition I get a different error: something like "No filesystem". I cannot repair the image with disk utility or asr, which both throw the I/O error. When I put the -verbose flag on the command I actually get a different error: "hdiutil: attach failed - No child processes".

I have output from both the -verbose and -debug flags but it is fairly long so I had to attach a link to avoid the 3000 character limit. No recovery system can get the data because it is both compressed and unmountable. How can I get the data back, and what has gone wrong?

-debug

-verbose