[Beowulf] Consumer vs. Enterprise Hard Drives in Clusters

[Nifty Tom Mitchell]

On Fri, Jan 23, 2009 at 01:08:05PM -0800, Lux, James P wrote:
> Subject: Re: [Beowulf] Consumer vs. Enterprise Hard Drives in Clusters
> > * Dramatically better vibration resistance.  >   is
> 
> Wouldn't the effect of vibrations from multiple drives depend
> greatly on the mechanical properties of the bay enclosure and
> the chassis itself?
> 
> Yes,but...
> 
>  For example, I have a 16 bay enclosure that's
> built like a tank (I know because I dropped it once). I would
> think that the vibration of one drive would barely be noticed
> by others.
> 
> ...stiffer and stronger might actually transmit vibration better and be worse!

Yes... 
Mounting of disks for reliability is interesting.
Quiet chassis often add rubber gromets to attenuate acoustic coupling to the chassis.
Way back c. 1982 a drive vendor recommended mounting their drive with
only three screws.  The fourth mounting point stressed the drive frame
from a plane and introduced seek problems. i.e. Our chassis design was 'too' stiff...
but it did survive a +30 foot drop to the runway from a 747 baggage loading ramp 

The logic was: Two points == line; three points == plane; four points == warped surface.


-- 
	Regards,
	T o m   M i t c h e l l