Spin down discs

[David Fletcher]

On Wed, 2014-06-25 at 22:29 +0100, Colin Law wrote:
> I believe, though I cannot point to any specific references, that it
> is considered better to keep discs spinning rather than winding them
> down, possibly for exactly the reasons you mention.
> 
> Colin
> 

I once read that the so-called fluid-dynamic-bearing in a hard drive is
pretty similar to the big end bearings in a car engine i.e. neither of
them have ball or roller bearings, just metal faces with a tiny gap
between them. The motion of the moving parts drags lubricating oil into
the gap so that so long as the hard drive/engine is running, there is no
contact between the moving parts, and therefore no wear.

My server only has a single hard drive, a 1TB Samsung EcoGreen. Apart
from a few hours when an excavator severed the 11kV feed cable to my
estate, it been running continually for the last 34,300 hours, with zero
errors. I believe that this is because there has been almost no contact
between the surfaces of that bearing, and almost no thermal stress to
the electronics.

Off topic, the same principles would make me very wary of buying a
vehicle with "start-stop technology". It has been well known for very
many years that the worst thing you can do to an engine is keep stopping
and starting it, yet these do it at every red light, just to save maybe
a thimble full of fuel. It must also hammer the battery. Is it worth it?
I don't know. Only time and reliability statistics will tell.

Dave


-- 

Lisa Simpson:- "They must have programmed it to eliminate the
competition."
Bart Simpson:- "You mean like Microsoft?"