How fit is your hard drive? Drive Fitness Test (DFT) is a technology that uses a PC-based software program that accesses Hitachi hard drive microcode to enable diagnosis of hard drive operations. This is perfect if you think you've been suffering from hardware or hardrive failure.
DFT microcode automatically logs significant error events, such as hard drive errors and builds a history of all reassigned sectors. This log is kept in a special reserved area of the drive which you can then use for technical analysis by the manufacturer or technician. DFT microcode also performs a mechanical analysis of the hard drive in real time. Parameters such as disk shift, servo stability, and Repeatable Runout (RRO) are calculated by reading the servo's Position Error Signal (PES) and analyzing the patterns in the PES. This is an interesting new test for hard drives - the signals that control the actuator are also used to analyze the mechanical status of the disk stack.
DFT microcode also supports the creation and use of a special protected "diagnostic partition" on the media. This volume is a separate range of sector addresses that can be used to contain the DFT software and other diagnostic software.
If you have a Hitachi manufactured drive, this tool can help you diagnose difficult problems although without a certified technician to analyse the results, they won't mean much to you.