[geeks] Speaking of Bad practice in the Win/X86 world

[Michael A. Turner]

> One of my clients was concerned that year-end processing was
> coming up soon and the VAX had been up for over 500 days.  The
> client wanted the system rebooted.  Never mind that there weren't
> any problems.
> -- 
> Eric Dittman
> dittman at dittman.net
 
	This does actually have a sick basis in probability math. Let me see
if I can explain this the way they are seeing it. If the chance of a server
failing on a given day is X, and the chance of it failing the next day is X
* 2, so at 500 days it is x * 500 and growing towards certainty. Now if we
look at the case of, if it has worked this far once before it will work
again this far, and define that as Y with and set it to the maximum value
the last value of days that was attained. you then subtract that from the
day value. you end up with (X * (days - Y)) which give you a negative
failure chance until after you pass the maximum time you have ever ran. 
	While this is not actually true, people who have not played with
systems a great deal and don't know thing like MTBF and the fact that
electronic parts do wear out will think it is. This is not even a stupidity
thing, it is just basic human nature to assume that if it has worked once it
will work again. Figuring it has been up for 500 days, they are worried it
will fail on the 501st, but if they reboot they get 500 days of error free
operation before they have to worry again. 
	It may not be right, but I can sympathize on why this is there
reaction.

Michael A. Turner
Systems Engineer WHRO
michael.turner at whro.org
http://www.whro.org