Got problem with installation. "No root file system is defined."

Question

I'm very new with Ubuntu and generally with linux. I saw ubuntu and it seems like this OS is really good and stable, and so I decided to install it alongside my windows 7 OS.

I have a few problems with the installation. Here is what I did:

1. I downloaded the 64bit version from Ubuntu official website, and burned it on a dvd.
2. I set the boot sequence to first load from my CD-Rom.
3. Ubuntu installation started, and I chose "Install Ubuntu" in the menu. (where there is also a "Try Ubuntu" option)
4. I clicked forward until I got into the installation type screen

As you can see, the installation wont show my actual details about my hard drive! I have 1 hard drive with 750 GB - 80 GB - My main drive with windows 7 OS 600GB - All of my stuff 20GB Free space that I saved for Ubuntu But the installation wont show that!

Answer 1

I've seen people with this problem before here on askubuntu (Ubuntu inslaller seeing the disk as one large unpartitioned space, not seeing any Windows partitions) and it usually was caused by Windows using Dynamic Disks, which is a proprietary MS extension to the standard MBR partitioning scheme.

Be careful, making any modifications to the partitions from Ubuntu installer when it can't see the existing partitions will result in data loss. You need to convert the disk to a "Basic disk" in MS terminology before proceeding.

Update: after some googling I see that Ubuntu installer should be aware of Dynamic disks and at least warn the user that it can't make modifications to the partition table. So the issue may be caused by something else. At any rate, you should not proceed until the installer sees all the partitions on the disk, forcing it to create new partitions on top will result in data loss.

Answer 2

I saw this too

sudo dmraid -rE

fixed it for me, from this thread:

Why doesn't the installer see all of my hard drives?

Th disk was messed up, and had some garbage metadata.