install CentOS 4 on external usb disk -- HOW TO

[harry2377]

Hi All,
I tried to install CentOS on an external USB disk attached to my Dell Inspiron.
I did 'boot: linux expert' and partitioned my USB disk.
Then I chose to install GRUB boot loader on the 'first partition of the disk' instead of MBR.
I did that because it wanted to install the GRUB loader on the /dev/sda while my USB disk is
/dev/sdb

After that, I completed the installation, rebooted with installation CD in rescue mode as 'linux rescue'

The I did all the stuff to make my new initrd with USB support as

mkinitrd --with-usb --preload=ehci-hcd --preload=usb-storage --preload=scsi_mod --preload=sd_mod /boot/usbinitrd.img 2.6.9-42.EL

Then I changed my GRUB conf file to point to my new USB initrd. And changed the boot sequence in BIOS to boot from USB Storage.

But when I boot the machine it gives me following error:

GRUB stage 1.5
Error: 15


Please tell me what am I doing wrong?

I also have one confusion. My Grub conf file has entries like

hd(0,0)
hd(0,1) etc.

should it not be hd(1,0) and hd(1,1) becaue USB disk in not primary disk. please explain ??


thanks
Harish