I have Parallels installed on my Macbook and have installed XP along with it, I was wondering if you could run 2 OS's within Parallels, namely Unbuntu.
I have run two at once, but it's a major drain on memory if anything. Set up the disks as expandable and disk space should not be an issue. I recommend 2GB of memory as a good standard for running Parallels.
Even when the guest OS (XP Pro in my case) is idling, Parallels still uses 10% CPU and 2.1G of virtual memory! I would not want to run 2 virtuals unless I really had to.
I am running Windows Xp and Fedora Core 6 right now on parallels. It runs fine. Although all I ever do when all 3 are running is text editing/browsing the internet. I am using a the conroe Macbook Pro w/ 2Gigs of memory. I have about 260 Megs of memory free still. So if you start running any hardcore programs in any OS you will probably start to slow considerably. I will probably upgrade to 3 Gigs of RAM when prices come down a bit.