[geeks] sun ultra 24

[Shannon Hendrix]

On Oct 17, 2007, at 7:35 PM, Dan Sikorski wrote:

> der Mouse wrote:
>>>> Double the processors *and* RAM and you have the method some
>>>> mainframes use.  Once in a while, even triple.
>>>>
>>> Seems a waste to me.
>>>
>>
>> Depends on the tradeoffs.  When downtime costs you tens of thousands
>> just for happening plus more thousands per minute, the reliability  
>> win
>> can be very much worth it.
>>
> Or if downtime just plain can't happen.  If my life depended on the
> operation of a computer, (I.E. Some sort of life support system) I  
> would
> want such features.

True, but my point was that even IBM discovered that many times it  
was more reliable and cost effective to have N machines rather than  
one that 'cannot fail'.

It's often difficult to tell which is the best solution.

I've been in an IBM shop when the mainframe died.  Everything...  
stopped...

If we'd had multiple machines instead, we'd have been able to keep  
running.

Of course, I've also been in a shop that used redundant hardware and  
fail-over setups where a crash in one machine led to cascade failure.

All of the redundant backups were were bug compatible... :)

The best one of all though: in one shop we had two machines in fail- 
over mode, and when it came time to upgrade them, management decided  
instead to just keep loading up both machines.

Yeah, by the time we really did have a crash, the load was too high  
for the backup.

Always remember that the best hardware in the world can be brought to  
its knees by a PHB.

-- 
"Where some they sell their dreams for small desires."