I'm running fsck_hfs on a very large volume. Unfortunately, there's an issue it appears to be unable to fix -- it reports it, loops back to start with Rechecking..., and reports it again, ad infinitum.

** Checking catalog hierarchy.
   Invalid volume directory count
   (It should be 513997 instead of 513998)
   Incorrect folder count in a directory (id = 27444570)
   (It should be 1 instead of 0)

I've tried adding the -r ("rebuild catalog btree") flag to fsck, but the issue still recurs.