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Hi I have recently installed ubuntu on my usb HDD which had 3 partitions on it, 1 of them having Ubuntu on it. I have been trying to boot up from it but it doesnt let me, I have installed the 12.04LTS on it.

Thanks in Advance, any help would be greatly appriciated


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Just to let you know this is the full release not the beta release :) – goeagles5 Apr 28 '12 at 2:26

Where have you installed the GRUB ? you could check in you grub conf files it should be in "/etc/default/grub"

Have you set your bios to start from you usb disk first if you installed grub on it ?

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yea my grub is in /etc/default/grub and in my bios it is set to boot up from usb devices, If you can think of anything else please let me know – goeagles5 Apr 28 '12 at 2:43

Not sure about installing to a USB HDD, but I had an error when installing 12.04 from a live USB where the boot loader was installed on the USB thumb instead of the Ubuntu partition. I used Boot-Repair based on these instructions. I just added the repository and installed it to my USB thumb, ran it, and was able to boot. It restored GRUB2 to the proper partition. There seems to be a bug in the installer, I've seen a couple of mentions to it today on Reddit.

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no I have already installed it but I cant even get to the login page so I cant do anything in ubuntu currently. Thanks for trying to help if you can think of anything else please let me know :) – goeagles5 Apr 28 '12 at 2:35
@goeagles5 Balthazar did suggest something else. Try booting and using the Boot-Repair tool even if only to use the Create a Bootinfo summary option. If you use this tool and still need help please update your question to include the link to the Bootinfo Summary. (It will look like The 6-digit number is the most important part.) – irrational John Apr 28 '12 at 2:46
@goeagles5 Did you use a Live-USB drive to do the install or a Live-CD? – Balthazar Apr 28 '12 at 13:44

You could try reinstalling grub onto the Ubuntu partition.

First boot into a live cd or usb stick and open a terminal.


 sudo fdisk -l

which will give output like:

Disk /dev/sda: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000a0832

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048  3886098431  1943048192   83  Linux
/dev/sda2      3886100478  3907028991    10464257    5  Extended
/dev/sda5      3886100480  3907028991    10464256   82  Linux swap / Solaris

If multiple disks appear look for the one with a Linux Swap to determine which is the local hard disk. The Linux partition will say 'Linux' at the last column.

Once you've found the device you need, you simply need to run

 sudo grub-install /dev/###

Again replacing ### with the device file relevant to you.

This should reinstall GRUB to the Ubuntu partition and restore your ability to boot to it.

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