[Dean]

OK... You HD is a shop manual for a car. MBR = the cover that tells you what brand/year/model it is. MFT is the table of contents, and index wrapped into one.

Now drill a hole through the spot where the page numbers are, cut the binding off, throw away the cover, table of contents, and index, shuffle the remaining pages into a big loose pile, light them on fire and then put them out by soaking them in bleach. Oh, and put on some inch thick carnival glasses that turn things upside down, backwards and blurred, have both your arms and hands broken and then reversed on your body and then try finding what you are looking for and reading it...

That's what it's like...

Anybody that trusts a mechanical device spinning at thousands of RPMs for months/years on end with tiny electromagnets on the end of featherlight arms to reliably store many billions of ones and zeros in the space of an index card with no maintenance and without failure over time is just plain silly.