You can IF you at least put the boot partition part of Ubuntu on the existing master drive. I haven't tried it, but since you can run Ubuntu from the CD without making changes to your drives, you could go through the setup and see if it lets you put all of the install on the slave drive by doing a custom partition when at that part of setup.
Here are two links that spell out the steps for you:
http://ubuntuforums.org/archive/index.php/t-275607.html http://www.oreillynet.com/cs/user/view/cs_msg/86709
Good luck!