How to boot Mepis from USB drive without USB boot but with Mepis CD

This is a thread adapted from an old post about performing a poorman's installation of knoppix 3.8 at

http://www.knoppix.net/forum/viewtopic.php?p=29244

which a little adapted also works for MEPIS. I should do this kind of installation for one of my colleague at work, who has to jump from older computer to knewer ones, and I was a bit surprised not to be able to find one post of this kind in the Mepis forums (if yes, I apologize, I didn't see it).

So basically: If you want to have MEPIS on a USB-Drive but you don't have a USB boot possibility in your BIOS, you have to make a kind of poorman's install called pivot root install; here is how to proceed:

1. install Mepis on your USB drive from CD or DVD as described in several threads in this forum and in the Mepis' lovers forum; also, at the end of the install process, do write MBR in the boot partition of your drive (f.ex. sda1) and not in root; don't use the initrd possibility;
2. reboot with the cd and the usb drive attached to your computer;
3. at Mepis logon, choose one line (the first one f.ex.) and erase it; then, only write the following word: single; hit 'return';
4. after Mepis loads, you will see a root prompt (in red); write the following, tipping 'return' at the end of each line; look carefully at each space:

mkdir /mnt/new_root
mount /dev/sda1 /mnt/new_root
mkdir /mnt/new_root/mnt/old_root/ (your have to type this line just the first time you log in your computer)
cd /mnt/new_root
pivot_root . /mnt/new_root/mnt/old_root
mount /proc /proc -t proc
init 5

5. after Mepis boot from your USB drive, you can free your cd; on some machine (laptop f.ex.) and for some unknown reason (to me), the cd may freeze after that procedure; on other machines, it may work as usual.

yours
zu