[Beowulf] Re: Cooling vs HW replacement

[Robert G. Brown]

On Fri, 21 Jan 2005, David Mathog wrote:

> > 	2. higher reliability - typically 1.2-1.4M hours, and usually 
> > 	specified under higher load.  this is a very fuzzy area, since 
> > 	commodity disks often quote 1Mhr under "lower" load.
> 
> Exactly.  It's very, very hard to figure out just how much reliability
> one is trading for the lower price.  Anecdotally, for heavy disk
> usage, it's apparently a lot.  Anecdotally, for low disk usuage,
> ATA disks aren't all that reliable either.

Has anyone observed that a megahour is 114 years?  Has anyone observed
that this is so ludicrous a figure as to be totally meaningless?  Show
me a single disk on the planet that will run, under load, for a mere two
decades and I'll bow down before it and start sacrificing chickens.

Humans don't live a megahour MTBF.  Disks damn sure don't.

   rgb

-- 
Robert G. Brown	                       http://www.phy.duke.edu/~rgb/
Duke University Dept. of Physics, Box 90305
Durham, N.C. 27708-0305
Phone: 1-919-660-2567  Fax: 919-660-2525     email:rgb at phy.duke.edu