It didn't start so well when upgrading my main test computer (AMD quad core 64-bit, 8GB RAM, 1TB disk) from Ubuntu 9.04 to Ubuntu 9.10 causes a failure in one of my 250GB sata drives. After a couple of attempts to repair Ubuntu 9.04 or install Ubuntu 9.10 from USB I resorted to install the operating system on another drive, considering that the problem had to come from the disk partition I was installing the OS onto.
This was effectively the case, as installing on another disk and partition allowed me to run Ubuntu without too much problem (apart from a disk boot order setting in BIOS that jumped a couple of times getting me to a grub dead-end).
But then installing VMWare Server 2.0, which I used for the last year, worked out with a few issues, and a major instability on the Tomcat based web-console. After a few days it became clear that Tomcat was not coming back to life and that I could no longer create new VM's. So I decided to give Virtual Box another try. I had installed VB back when Innotek was bought by Sun Microsystems. Then bridge networking was even more challenging than with Qemu and KVM, and NAT was very limited.
So I installed VirtualBox Open Source edition (3.0.8) from a standard Ubuntu package mirrors and off I went to reset my test environment from VMWare to VirtualBox. Creating a single master Windows Server 2003 virtual disk (VDI as opposed to VMDK) was fast, and cloning it was not complicated, albeit it requires using vboxmanage as opposed to a single copy and paste with VMWare.
Settings the VM's, configuring networking was a hassle free process. And starting or stopping the machines is also quite easy, given Virtual Box comes with a native console in opposition to a web-stack.
And to close this brief discussion there is one feature that won me over: seamless mode. Now rather than talking about it here's a screen shot:
I suspect this requires a little bit of explanation. So the background image with the elephant is on my Linux desktop (the VM host). The Windows menu bar on the bottom is part of the VM running in seamless mode as well as the internet explorer and add remove program windows. At the top status bar belong to Linux and on the bottom right hand corner we can see my GDeskLet panel and my 8 virtual desktops: #1 is running Chrome, #2 is a legacy VMWare image running, #3 to #6 are 4 virtual machines running in seamless mode whilst #7 is free (I use it a lot with gimp for screen shots and comments) and #8 is for IM (Skype, Gtalk and MSN).