problem booting from external hard drive "cannot find device"

fumungacheese · 06-14-2011, 02:14 PM

I've recently installed Zorin onto my external hard drive to use with my laptop. I got everything installed and working good, but I'm having 1 problem. Everytime i got to start up my laptop, whether it's from hibernate or actually starting up, i get this message if my external hard drive is not properly hooked up :

error: no such device: 2c1bd860-2b88-4275-8d3e-a9b5b8cc1697
grub rescue>

then it acts like a command line. i usually have to plug in the ext. hdd. until it's up and running and then turn my lap top off and on numerous times until it goes to the screen where i can choose which OS i want to use.

I THINK i know the problem, which is i have some sort of boot manager installed on the ext.hdd. that needs to be on the laptop's internal hard drive, but i have no idea where i could find it or where I'd move it to even if i did find it.

also my system information is as follows:
windows 7 OS 64 bit
HP pavilion dv5
... i think that's all that really needs to be known. any other questions just ask

TobiSGD · 06-14-2011, 02:26 PM

Quote:

Originally Posted by fumungacheese

I THINK i know the problem, which is i have some sort of boot manager installed on the ext.hdd. that needs to be on the laptop's internal hard drive, but i have no idea where i could find it or where I'd move it to even if i did find it.

The problem is vice-versa. You have installed Grub (the bootloader) to your internal disk, not your external. The bootloader tries to load parts from the external drive, which obviously fails if the disk is unplugged.
To correct that you have to first install the bootloader to the external disk and then restore the Windows bootloader.

jefro · 06-14-2011, 03:43 PM

I think tobisgd is correct but I am not sure why it is doing that.

May be possible to fix grub.

What does command ls show?

Can you use find command?

fumungacheese · 06-14-2011, 04:13 PM

tobiSGD: how do i go about doing that?

jefro: yes i found the terminal. and it says this:
jake@jake-HP-Pavilion-dv5-Notebook-PC:~$ ls
Desktop Documents Downloads Music Pictures Public Templates Videos
jake@jake-HP-Pavilion-dv5-Notebook-PC:~$

TobiSGD · 06-14-2011, 04:22 PM

First boot into Ubuntu and post the output of

Code:

df

launched in a terminal. This way we can see the naming of your harddisks.

fumungacheese · 06-14-2011, 04:49 PM

Filesystem 1K-blocks Used Available Use% Mounted on
/dev/sdb5 353186900 3800972 331445040 2% /
none 1853136 336 1852800 1% /dev
none 1897444 372 1897072 1% /dev/shm
none 1897444 216 1897228 1% /var/run
none 1897444 0 1897444 0% /var/lock
/dev/sdb2 104855548 91292 104764256 1% /media/other OS
/dev/sdb1 990343672 407427616 582916056 42% /media/Elements

TobiSGD · 06-14-2011, 04:58 PM

OK, we see that your external drive is /dev/sdb, so you can install Grub on it with

Code:

sudo grub-install /dev/sdb

After that you have to restore the Windows bootloader. To do that you have to boot from your Windows DVD and go to the recovery-console. Launch the command

Code:

bootrec.exe /fixmbr

and you should be able to boot Windows without plugin in the USB drive.
To choose Ubuntu at startup just plug in the USB device and choose it from the boot-menu after starting the machine. On my HP I get the boot menu with pressing F10 at startup, but this may differ for you.

fumungacheese · 06-14-2011, 05:24 PM

You are unbelievably amazing! Everything started up good

thankyou so much

TobiSGD · 06-14-2011, 05:30 PM

You're welcome. Have fun with Linux.