After many tries I succesfully managed to get my iMac 21.5 2011 with this configuration:
  • OSX (Mountan Lion)
  • Windows 7
  • Ubuntu 12.04
  • NTFS shared data partition

The shared data partition is handy so I can put my media there (music, movies, pictures) and they are accessible from any OS installed on my mac.

This involved many hours of trial and error, configurations and some stuff to setup. I wrote some notes months ago, but since I want to share what I did, I need a tester with some knowledge and with only OSX installed to help to replicate the steps I did.

If some volunteer is available and want to try, let me know!