[CentOS] boot thumbdrive with CentOS 7 ISO???

Sun Dec 13 21:48:25 UTC 2015
ken <gebser at mousecar.com>

The big picture is I'm wanting to boot centos 7 and install kvm.

So far I've created on this new laptop a big, empty partition; in the 
BIOS enabled legacy booting and disabled UEFI; also in BIOS under Legacy 
Boot Order set "USB diskette on key/USB hard disk" on second priority. 
I've tried to boot from a usb thumbdrive three times and it failed all 
three times.  I'm not understanding what's wrong.

I tried all three methods below as root using CentOS 5.11, copied it to 
the thumbdrive with:

dd if=CentOS-7-x86_64-Everything-1503-01.iso of=/dev/sda bs=1024

(Tried this because some webpage said)

isohybrid CentOS-7-x86_64-Everything-1503-01.iso

dd if=~CentOS-7-x86_64-DVD-1503-01.iso of=/dev/sda

None of these successfully booted.  Instead they ignored the flash drive 
as it wasn't there.

Documentation in various webpages I found gave different recipes for 
creating the thumbdrive contents (many of which didn't make sense to 
me).  Does anyone have experience with success with this...?

Thanks much.

PS. Also in the BIOS, should I enable Virtualization Technology?  I'm 
sorting guess I should.  The Windows docs recommend not to.  I'm 
thinking though it would be preferred for KVM.  What's the certain verdict?