I am running Ubuntu 14.04. Using GParted I have copied the Ubuntu partition to an external HDD connected via USB.

The partition with Ubuntu on the external HDD has its flag set by GParted to "boot". There is one other partition on the external HDD which contains non-bootable Windows Xp data. The Grub bootloader correctly shows the operating systems on the external drive and also on a second internal HDD. The Ubuntu partition on the external HDD will not boot (I want to use this partition as a backup which I will periodically update).


It doesn't show the external USB drive at all - only the 2 internal drives.

There is no response to sudo blkid -c /dev/null -o list

  • Have you tried creating a boot partition and flagging it appropriately? Try this, boot into the Ubuntu system which works and run sudo parted -l this will give you a concise summary of the partitions. What you're looking for is partition table msdos or GPT. Add a screenshot of this information to your question or upload it online and post the link and I will provide assistance from there. – user271219 Oct 1 '14 at 14:21
  • 2
    Grub does not use boot flag. But if you copied partition, you may have duplicate UUIDs which are not allowed. Post this in first question: sudo blkid -c /dev/null -o list – oldfred Oct 1 '14 at 16:10

Multiple errors trying to prevent it.

Grub should be installed on /dev/sda

Then left to do:

Disconnect the internal disks, and install Grub on the external, and this /dev/sda, previous change in the /etc/fstab file the UUID of the partition.

Install Grub in the root partition of the external, previous change in the /etc/fstab file the UUID of the partition, and then from an internal hard disk session run:

sudo -i

In order to incorporate the external disk operating system.

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