[svlug] archive media of choice for 10~100GB

John Conover conover at rahul.net
Thu Jan 1 15:04:01 PST 2004


See:

    http://www.dscc.dla.mil/Programs/MilSpec/SmdOverview.html

about Mil. Std. 38510 for starters. Google will find others.

Almost all space electronics, which is designed for a total unattended
system operational life of 25 years, (meaning the theoretical MTBF is
5-10 times that,) references the 38510 document for the QA methodology
of the HW/chips.

Note that the failure model of 38510 for electronic stuff assumes
ergodicity, (e.g., the century failure rate can be determined by
measuring the failure rate of a hundred systems for a year.) It isn't
so-as pointed out by Karen-but its a "reasonable" stochastic modeling
assumption, based on a 2 year QA process, and a way to do things that
has a "reasonable" documented history in the industry. I mean, Voyager
is still beeping at us from the edge of the effects of the sun in deep
space, and has never had a Ctrl-Alt-Del.

As rough cost numbers for 38510/8002-A, multiply the consumer cost at
Fry's by somewhere between a hundred and a thousand X, (more for the
8002 "man rated S" space spec.)

        John

Chris Palmer writes:
> 
> Karen Shaeffer writes:
> 
> [entropy effect on magnetic and solid-state stuff]
> 
> Is there any chance you can cite a reference for this, or is there some=20
> basic textbook that explains it all? Thanks.
> 
-- 

John Conover, conover at rahul.net, http://www.rahul.net/conover/




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