[CentOS] how to dual boot centos with redhat?

From: hadi motamedi <motamedi24 at gmail.com>
> Actually, my redhat version is an old one that does not recognize usb disk (but 
>
> my centos can). So I thought if I can install redhat on one of my centos 
> partitions and then copy its contents to usb disk via 'dd if of' utility.Can 
>you 
>
> please let me know how can I install redhat on my centos?

So, you want to use an OS that "does not recognize usb disk" on... a usb disk?

JD