Ubuntu on an external drive---how to?

[Derek Broughton]

Kanda Kumar V wrote:

> I've tried installing the boot loader (the grub) into /dev/sda (my
> external drive) and when i reboot after the installation finishes.. i'm
> getting grub error 17. i can't boot from my external USB device... i've
> set my boot priority in BIOS as 1. USB hdd 2.CD drive 3.internal disk(the
> windows one)...
> 
> my external drive is an Western digital USB external HDD.

Grub error 17 is "can't mount partition" (please post the error messages, we
shouldn't have to go looking)

Which makes one wonder if you really have grub pointing at the right
device/partition.

Regardless of whether /dev/sda really is the USB drive, there are a couple
of other options.

1) You probably can't boot from a USB device if usbstorage, and probably
other modules aren't in the initrd image in /boot.  I can't begin to
imagine how you make sure the right modules are there.

2) You might try installing grub to the USB drive's partition superblock,
rather than the MBR, and chaining from the internal drive's grub.  The
entry in the internal drive's boot menu.lst would look like:

title           USB Boot
root            (hd1,0)
makeactive
chainloader     +1

-- 
derek