TO-Tech Blog Todd Ogasawara’s Tech Blog

16Jan/0812

Red Hat 5/CentOS 5.1 and Microsoft Virtual Server 2005 R2 SP1

Parallels Desktop for Mac and VMware Fusion (Mac)/Workstation (PC) don't seem to have issues with the current generation of Linux distros. But, Microsoft's Virtual PC and Virtual Server do not, unfortunately. And, since most of my work is using Virtual Server, I've been spending a bit of time hunting for information and asking questions. Most of my information has come from reading Ben Armstrong's (Microsoft Program Manager in the Virtual Machines group) blog. But, I haven't seen all the information I've collected there and elsewhere collected in one place to help others trying to run current generation Red Hat Linux distro derivatives (RHEL5, Fedora, CentOS) under Virtual PC and Virtual Server. So, here's what I've found so far to get these Red Hat based distros working. I've tested all these items using CentOS 5.1 and one or two using RHEL5 or Fedora. Make a backup of your working (or semi-working) VM/VHD before trying anything mentioned below.

  • Degrade color depth from millions of colors (32-bit) to thousands of colors (24-bit). This is due to an issue with the S3 graphics chip emulation. If you need to make this change after the fact, use SSH to get to your odd looking (display-wise) VM and use system-config-display to change color depth from 24-bit to 16-bit. This change will be reflected in /etc/X11/xorg.conf
  • Add the following kernel parameters:
    • clocksource=pit (this is to help deal with the clock sync issue)
    • i8042.noloop (this is to allow using a mouse in X windows) You can read more about this solution in this article this article and this Red Hat bug thread.
    • If you need to apply the two kernel parameter changes after the fact, you can edit /boot/grub/menu.list and add both parameters to the kernel line

The clocksource option helps but does not entirely solve the clock drift issue. I end up having the clock resync with a time source once an hour as an added workaround. I hope this collection of findings help's others run current generation Red Hat related distros under Virtual PC and Server.