[CentOS] md raid 10

[m.roth at 5-cent.us]

John R Pierce wrote:
> On 03/08/12 6:33 AM, m.roth at 5-cent.us wrote:
>>> >  ok, so 3 x 48/64 core servers uses the same power as 6 x 4/8 core ?
>>> >  thats still major win.
>> Um, no - that's what I'm saying is*not*  the case. The new suckers drink
>> power - using a UPS that I could hang, say, 6 Dell 1950's off of,*if*
>> I'm lucky, I can put three of the new servers. And at that, if a big jobs
>> running (they very much vary in how much power they draw, depending on
>> usage), even with only three on, I've seen the leds run up to where
>> they're blinking, indicating it's near overload, over 90% capability.
>
> ok, how do you figure 3 48 core modern servers are not more powerful
> computationally than 6 8 core servers?   the 1950's were "cloverton"
> which were dual core2duo chips, 2 sockets, at ~ 2-3GHz, for your 8 cores
> per 1U.

I'm sorry, but to me, the above is a non sequitur. I was talking about how
much power the servers drink, and that the UPSs that I have can barely,
barely handle half as many or less, and I'm running out of UPSs, and out
of power outlets for them in such a small space (that is, a dozen or so in
each rack), without trying to go halfway across the room.
>
> now, I dunno what your 48 core servers are, if thats really 2x12 cores
> with 'hyperthreading', then those extra threads are NOT good for intense
> numerical compute work as they share the FPU, but even those 24 cores
> should be faster than twice as many 8 core systems.
>
http://www.newegg.com/Product/Product.aspx?Item=N82E16819105264

      mark