[Beowulf]Infrastruture planning for small HPC 40/100 gigabyet eyhernet or Infiniband?

[Nifty niftyompi Mitch]

On Sun, Jul 27, 2008 at 09:28:07PM +0200, Eugen Leitl wrote:
> On Sat, Jul 26, 2008 at 09:15:23PM -0700, Nifty niftyompi Mitch wrote:
> 
> > Did I read this correctly? 
> > Are you cutting holes in the walls of a home.....?
> 
> Real homes have cable ducts -- I'm limited to drilling through walls.
> Unfortunately, due to lousy electric installation I'm stuck with 
> severe ground loop issues (I catched that too late orelse
> I would have put in a heavy ground wire strung along the CAT 6/7). 
> Galvanic separation would be a god-send -- but for the price 
> tag, and unavailability of GBit polymer optical.
>  
......
> 
> CAT 6 is great, except if you see sparks when plugging in RJ-45s.
> Also, most systems tend to shutdown spontaneously overnight when
> on such dirty network.
>  
> > Also all wires in the wall MUST be safety rated for such use.
> 

OK if you have severe ground loop issues you must rethink
what you are doing!   Ground loops generated by a bad power
install can have almost unlimited currents and present
a serious fire hazard.  Get the problem fixed.

Contact a qualified electrician and find out what the root cause is.
AFAIK most network switches do provide MAC level isolation at the physical 
layer so I am confused and _concerned_ about your comment about seeing sparks
at the RJ-46.   Get the problem addressed promptly.


-- 
	T o m  M i t c h e l l 
	Looking for a place to hang my hat.