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could anyone help me to boot ubuntu-9.04 from usb hard disk?

This disk contains /boot primary partition. During ubuntu installation I used "Advanced" button and asked to install GRUB to the /boot partition. Later I checked whether GRUB files are really present in this partition. They are.

However, I get stuck while trying to boot. The boot menu ("ubuntu generic version", "ubuntu recovery mode", etc...) is not shown. Instead I am thrown to GRUB minimal bash-like version.

I feel at a loss and have no idea why I am pointed to this minimal version. Can anybody prompt me what to do?

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migrated from Oct 22 '09 at 2:23

This question came from our site for professional and enthusiast programmers.

up vote 2 down vote accepted

Assuming you have the valid menu.list, I think the commands you want are:

root (hdX,Y)
setup (hdX)

where hdX is probably hd0 or hd1 and Y is the partition number, starting from 0. Note that grub numbers primary partitions (0,1,2,3) and logical partitions (4,5,6,7).

The 'root' command will check for the right partition type. The 'setup' command will check for the right files in /grub or /boot/grub (on that partition).

For example, if your internal hd contains non-linux windoz stuff and the first partition on your USB drive is /boot, then try:

root (hd0,0)

and if that works:

setup (hd0)


root (hd1,0)

and if that works:

setup (hd1)

Then reboot and select the USB drive at the bios boot menu.

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Thank you for a detailed answer. It works! – user15001 Oct 22 '09 at 21:22

This happens when the grub binary is executed and it can't find the directory containing its configuration. Usually you end up with the disk number being off (ie. hd1 vs hd0, etc when installing grub. Note that this is separate from the grub.config ).

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To add to that: if you type configfile (, hit tab, and then enter the correct partition, you should be able to load the menu. (This isn't permanent, of course.) – ephemient Oct 21 '09 at 20:46
Err, enter the correct partition and path, that is. Something like (hd1,0)/boot/grub/menu.list is likely. Tab completion will help along the way, and find /boot can help too if you have no idea which disk/partition to choose. – ephemient Oct 21 '09 at 21:15
Thanks a lot for spending time on my question. Unfortunately, my reputation score is too low to mark your answers as usefull. But they are. – user15001 Oct 22 '09 at 21:27

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