Innochecksum is a small undocumented (at least in the manual) utility that verifies the checksum of ibdata file pages. I stumbled across it the other day while wandering through the source tree. It has a small bug that prevents it from being able to check files larger than 4G. This patch fixes it in linux. Someone that knows more about large file support in different OSs please comment on the patch.
It lives in the extras folder in the MySQL source. Here is the credits comment:
InnoDB offline file checksum utility. 85% of the code in this file
was taken wholesale fron the InnoDB codebase.
The final 15% was originally written by Mark Smith of Danga
Published with a permission.
I think as a community we need to make sure that tools like this are kept in the forge and actively developed. More on this when I have had some sleep.