[GTALUG] war story: keyboard failure leads to sustained mayhem

[D. Hugh Redelmeier]

This story could be told in order of discovery.  That would be more fun.  
But I'm going to explain it as plainly as possible to make it more useful.

I have a KVM switch (Keyboard Video Mouse) that lets four computers share 
one keyboard, display, and mouse.

Unbeknownst to me, the keyboard started generating a rapid stream of ESC [ 
D (back arrow) sequences.  I'm not sure whether it is all the time or just 
some of the time.

The next time I booted one of the computers, it seemed to fail to find its 
hard drives.  It was more than a decade old, so rather than fixing it, I 
replaced it.  I now think that a continuous stream of backarrow keys 
confused the BIOS (or the RAID card BIOS) when the machine was booting.  
But at that time, it seemed to be a simple case of old hardware wearing 
out.

Another computer had different symptoms, but again showed disk problems.  
When I did disk diagnostics, I was puzzled by the results: no problem.

Eventually, I found the keyboard problem and have thrown the keyboard 
away.  I have no idea how long it had been misbehaving.

Lessons re-learned: 

- symptoms don't always point clearly to the disease.

- conclusions should remain provisional

- it's amazing how long you can overlook a stuck keyboard key

- apparently I really only use the KVM for booting; it would be
  nice if PCs had been designed to be happy headless