Possible Duplicate:
Installing Ubuntu on external hard disk

If I were to install Ubuntu 11.10 on my 500GB external hard disk, will grub mess with the MBR of Windows 7 in my internal HD?

I once dual booted WindowsXP and Ubuntu in two different internal disks connected to the same PC. GRUB automatically became the default boot loader.

I don't want to mess with my windows7 installation. I just want Ubuntu on my external HD and GRUB should load only when I boot from my external HD.

Also, should the entire external HD be used for the installation or will a partition of say 30GB work.

I have my Windows 7 auto backup in the same external HD too. Does Windows make the external HD bootable or something while storing the system images and backup files in my external HD, because then installing Ubuntu also on the external HD might cause problems.

  • Here the user says you need to have the same configuration of HDs. So my internal will be sda and external will be sdb. Which means Ubuntu will try to mess with sda's bootloader too doesn't it? – Astromaz3 Feb 2 '12 at 17:47

One solution is to make sure that the boot loader is installed to the MBR of the external disk.

If possible remove the internal disk before installing Ubuntu, make sure that Ubuntu only finds the external disk during the installation, when you want to run Windows7 you need to select the internal disk as boot device on your BIOS, when you want to run Ubuntu you need to select you external USB disk as boot device on the BIOS.

This way you have 2 disks, separate, both with information on the MBR and a boot loader but no interference between the 2 of them.

About the sizes and partitions, if you are making backups to the external disk I recommend that you make a 3rd one on another drive just to be sure and during the Ubuntu installation choose "Install Ubuntu along side with Windows", Ubuntu will try to re-size the partitions on the external disk and install it self to the space you assign.

If you are not going to make a intensive use of Ubuntu for now 30Gb sounds good enough, you can re-size the partition later on to take more space from the backup partition later on if needed.

| improve this answer | |
  • Thanks for the answer. I'm trying to install Ubuntu on my laptop. I don't think it's possible to remove my internal HD. So GRUB will mess up the internal HD's windows 7 boot loader right? Say after installation if I use EasyBCD and edited the bootloader info while in windows, then the interference between the two will be solved right? – Astromaz3 Feb 2 '12 at 17:58

Not the answer you're looking for? Browse other questions tagged or ask your own question.