Can't use a particular partition for Ubuntu installation

Question

I am trying to install Ubuntu 10.04 as a second OS on a laptop that has Windows 7. In Windows, I have created the below partitions:

C: -> NTFS - 225GB (Windows installation)
D: -> recovery partition
F: -> NTFS - 175GB User Data 
G: -> NTFS - 50GB This is where I want to install Ubuntu on.

In the Ubuntu Install/Setup process (using a 10.04 live CD) , the last partition (on G:) is not shown separately, but seems to be grouped together with the other NTFS partition. I therefore can't choose the 50GB partition as the Linux installation root.

I tried leaving the partition as unallocated space (unformatted without any file system written on it) but Ubuntu still did not recognize it during installation.

1. How can I format this 50GB partition in Windows (either using Windows Disk Manager or some other disk partitioning tool) so that Ubuntu setup can see this partition as a distinct one and allow me to install Linux on it?

2. Can formatting this 50GB partition as ext2/3/4 help? If yes, what tool on Windows can allow me to do that?

3. What other solutions do I have to install Ubuntu, whilst maintaining my Windows 7 partitions?

I read online that there is a limitation that hard drives can have 3 partitions and 1 extended partition. The extented partition cannot have any OS (bootable) so you can't use that for Linux. How can I make one of the existing partitions extended? My thoughts are I could try making one of the NTFS partitions (only used for data storage, no OS) extended, then be able to use the 50GB partition for Linux.

Answer 1

I would do one of two options:

1) Install Linux in a virtual machine. There is free VM software such as VirtualBox, or commercial software like VMware Workstation.

Pros of a VM:

• Run the guest OS (Linux) at the same time as the host (Windows), don't have to reboot to switch. You can even have a shared clipboard for copy/pasting data between the two.
• No need to change existing partitions.
• Easy to make and restore VM backups, or completely reinstall the guest OS.

Cons of a VM:

• The guest OS won't run quite as fast as if it was installed as a dual boot option.
• The guest OS sometimes can't use advanced features (like full graphics acceleration).

2) Rearrange your existing partitions so that Linux can go on one of the first three. To do this you will probably need an external HDD you can temporarily move data onto. I would backup all the contents of your "User Data" partition, then delete that partition, as well as the extended 50GB partition (and maybe the recovery partition as well if you don't feel you need it).

Then re-create the 50GB partition for Linux; this time it will be one of the first three partitions. Use the left over space to make an extended partition for the User Data to go back onto.

Answer 2

If you created the partition in the Windows partition editor, it will be marked as a Windows partition and Ubuntu won't install on it. Boot the Ubuntu installer, which will load gparted (or just load gparted from any Linux LiveCD) and delete the fourth 50GB partition, then create a new one of type "ext2" (which includes ext3 and ext4). Ubuntu should install on that, no problem.

BACK UP YOUR WINDOWS VOLUMES FIRST.

If you can't do this, open a terminal from a Linux LiveCD and type

sudo fdisk -l /dev/sda

where "sda" should be replaced by the correct device. Post the result of fdisk -l in an edit to your question.