> How do you "spin down" a HD while power is on?

I thought this was one of the things that professionals know
I suppose I was wrong, or then you are not professional

hdparm -y /dev/hdb

>> I suppose not, but please speculate and analyze the events of
>> hotswap ordinary IDE disk.
>
> It would likely destroy the motherboard, and maybe the HD.

How would it? can you answer for that? What parts of the motherboard?

>
>> Professional electricians are welcome to join this conversation and give
>> your opinions!
>
> This question is just as stupid as your other one about PCI cards. My
> opinion is that you are an idiot.

OK, its your opinion and then?