I have two partitions on my disk:
/dev/sda1 30G /dev/sda3 270G
Somehow I've installed Ubuntu 12.04 on each of the two partitions. So now I have two Ubuntu installations which are both listed on the grub boot menu. I would like to erase one of the partitions (
/dev/sda3) and use it just for data backup. I would also like to have only one entry for Ubuntu in the grub menu so that I don't have to choose it every time I reboot. How can I achieve this?