[X4U] Re: External HD Reliability?

[Bill Bauldry]

On Feb 27, 2008, at 2:55 PM, "Zane H. Healy" <healyzh at aracnet.com>  
wrote:

> I'm curious if anyone has any comments about the reliability of
> external HD's, especially the Lacie, and Western Digital models.  I
> really need a couple external drives for photo vaults, and am trying
> to decide if I should buy something, or build something.


I've run a LaCie network storage piece for the dept and have had  
several external LaCie drives over the years all with no problems. I  
also picked up a couple of Western Digital MyBooks at a very nice  
price from our local Staples to use with TimeMachine; they've run  
quite well, too. Although, I understand WD has some "issues" with the  
phrase the "customer knows best" when it comes to Mac people.  
OtherWorld Computing does good work for little more cost, but they  
just may be worth it.

Something I do find very amusing is the "Mean Time Before  
Failure" (MTBF ) statistic that the hard drive manufacturers promote.  
A common figure is 1,200,000 hours MTBF for a drive mechanism. A  
little calculation is appropriate:

	1,200,000 hours * (1 day/(24 hours)) * (1 year/(365.24 day)) = 136.89  
years

So the 'mean time before failure' of a hard drive (from nearly every  
vendor) is over a century. Talk about quality control!
Or mayhap there be a little bogosity to the figures there, Matey.  
Arrrrrrr.

Bill
_____________________________________
Wm C Bauldry, PhD
Professor of Interesting Stuff
Department of Mathematical Sciences
Appalachian State University
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