A number (all?) of virtualization products from Microsoft, Parallels, and VMware are having problems with recent Linux distro releases such as CentOS 5.0 (Red Hat Enterprise Linux clone) and Ubuntu 7.04. The main visible problem seems to have to do with the X11 windowing software. CentOS 5.0 appears to install correctly but X11 does not display. Instead, you get a text prompt that gets you to the shell. Manually attempting to start X fails too.
Here’s what worked for me though. I installed the older CentOS 4.4 first. Then, I booted from the 5.0 ISO and upgraded the 4.4 system. I’ve tried this twice: Once using Virtual PC 2007 and once using Virtual Server 2005 R2 SP1 Release Candidate. Both upgrades completed successfully and left me with a functioning X11/Gnome environment. Be sure to run “yum check-update” and “yum -y upgrade” after the upgrade. There are a bunch of components that need to be updated after CentOS 5.0 is up and running.
Ubuntu 7.04 Linux is another story. Although I’ve read reports of people getting this to install and running under Virtual PC 2007, I have not as much luck as them. I was able to get it installed but the X11 login screen was unusable for further work. I even had problems getting Ubuntu to run on a physical computer. I took an old Dell Latitude L400 currently running Ubuntu 6.10, wiped it out, and installed 7.04. However, a long series of kernel error messages is displayed on boot and the system never comes up correctly. It does, however, appear to install and run ok on an old Dell Dimension 4000 desktop PC. It is nowhere near as clean as the upgrade from 6.06LTS to 6.10.
I tried the upgrade path method with Ubuntu by installing 6.06LTS in Virtual PC 2007 first and then upgrading using gksu “update-manager -c” too. That resulted in a bunch of errors related to access issues to Gnome icons and OpenOffice files. Ultimately, the upgrade process appeared to fail and abort with a message about an unstable system. However, Ubuntu does boot into a normal looking X11 login screen. But, as noted in various web bulletin boards, the mouse does not work and you can’t effectively navigate Gnome’s GUI.