http://united-geeks.org/blog

Short abstract:
This post has a double purpose:
1. YES, you can use the opsi VMWare Appliance in VirtualBox (a 10min google search did not yield one hit of somebody who did this before, so: eat this google!)
2. It won't boot without modification, the very easy solution is below

Long version:
Wanted to check out opsi without installing it. So i downloaded the VMWare image that is also provided. However, i got rid of VMWare about a year ago in favour of VirtualBox (there were plenty of reasons for that...). The good thing about VirtualBox is also that it allows to use VMWare's vmdk files as virtual harddisks, so i thought it should be easy to check it out. After setting up the new machine in VirtualBox with the downloaded opsiserver.vmdk I booted for the first time and was greeted by:

Waiting for root file system ...

The fix is really easy though, once you understand what the problem is: the underlying system of the appliance is a Debian GNU/Linux with Grub as boot loader. The problem is that the original VMWare installation used virtual SCSI or SATA devices, so the line in /boot/grub/menu.lst contains /dev/sda2. On VirtualBox (at least with the default config) the system uses virtual IDE disks, so you need to simply change /dev/sda2 to /dev/hda2. To do this on every reboot you can use the built-in editor of grub (press "e") and change the device. Once you booted successfully, you can change it permanently by editing /boot/grub/menu.lst.

Now comes the fun part: learning how to use opsi to save me time. But as far as I know / read about it, it's just what I am looking for. I guess it even makes sense in a small environment like ours here (6 Windows clients but loads of common software that needs to be installed on all our machines...). Maybe I will blog about it again after I got to know it better.

Ah, versions used:
VirtualBox 3.0.8 r53138 (equals app-emulation/virtualbox-bin-3.0.8 in Gentoo)
opsi3.4-servervm (2009-09-16)