Although not a performance-tuning program per se, the utility
badblocks checks an (preferably) unmounted partition for bad blocks. It is not recommended that you run this command by itself, but rather allow it to be called by
fsck. It should be used directly only if you specify the block size accurately; don’t guess or assume anything.
The options available for
badblocks are detailed in the man page. They allow for very low-level manipulation of the file system that is useful for data recovery by file system experts or for file system hacking, but they are beyond the scope of this chapter and the average user.