Problem with the EFI system partition's file system

I’ve had a 3TB WD My Book Essential drive plugged into my Airport Estreem for a while now as a media drive and suddenly it has stopped mounting and says that there is a problem with the EFI system partition’s file system.

Clicking repair in the disk utility appears to fix it, but when atttempting to verify the disk after repair it gives the same error and I can no longer access any files on the disk.

Does enyone know how to fix this error?  I’m on OS X Lion 10.7.2 and everything was working well until a couple days ago.  As far as I can tell no system updates were installed that would have caused this…

Sounds like file system corruption to me… I’d just make a clean GPT partition on Disk Utility.

Sounds like other people are having issues with 3TB drives & Lion and it may be fixed with the 10.7.3 update.  More info here: https://discussions.apple.com/thread/3222378?start=75&tstart=0

If I do have to “make a clean GPT partition on Disk Utility” will I loose the data that is on there now?  If so that’s not an option.  This drive has all the photos & video from when my daughter was born 2.5 years ago on it as well as my entire iTunes library.  I need to get these files off before I do anything that would erase them.

Guess i’ll just have to wait and see if the update resolves the issue.

If PizzaMatrix is correct, then you might look online for a partition recovery software, and see if that restores the partition.  However, if you have corrupted files, you won’t be able to recover them.