Your going completely wrong with this. You need a ps3 with Linux and the Terminal App. Thats all I'm going to say.
I really hate it when people make it seem like they know exactly what they're doing then only give one hint and say "I can't say anything else" or some bull like that.
If you're talking about getting the ISO, it doesnt work.
There is no existing way to run ISO's of ANYWHERE including an external HDD or anything.