I’ve been putting off writing about VirtualBox for a while now (mostly because other topics have come to the front of my mental queue.) But when I finally started poking around at some of the nuances of this tool, I realized that I had to bring it up here on TechRepublic. One of those “nuances” (if you can actually call it that) is Seamless Mode. To sum it up, Seamless Mode is amazing. If you’ve not tried it (or VirtualBox) you are missing out on a feature that can help to make the guest operating system seem, well, seamless within the host.

But seamless isn’t something new. VMWare started it with their “Unity” mode (which in turn is a direct copy of the “Coherence” feature in OS X’s Parellels Desktop.) But VirtualBox does all of this under the GPL 2 (If you’re using VirtualBox OSE) and for free.

I have used plenty of virtualization tools. I started using VMWare back when it was first released. I had to do this when working in an environment that required I use a certain template for documents that I had trouble using in Linux. With the help of VMWare I was able to use this template in a guest Windows operating system on a Red Hat host. Back then there was no “Unity”, “Seamless”, or “Coherence” (heck there wasn’t an OS X at that point.) so I was always working in a window within a window within a desktop. When other users would see this it would confuse them…very common reaction to new users trying to work with virtual machines. The very concept of VMs escape them. Imaging having to explain to an new user they are working on a “program in an operating system within an operating system”. For the average user this is too much information. And that’s why the VirtualBox seamless mode is a perfect solution for a problem that could easily plague admins.

Take a look at Figure 1. This is Windows XP running as a guest operating system on a Ubuntu 9.04 desktop installation. As you can see XP is running in Window’d mode so it is an “operating system within a window on a desktop”. Sure users can make use of it but for new users it’s going to be one more stumbling block amid an already seemingly insurmountable amount of stumbling blocks.

Seamless Mode strips this one stumbling block away from the new user by incorporating the guest desktop in with the host desktop. Take a look at Figure 2 which shows the guest Windows XP running in Seamless Mode on the Ubuntu 9.04 host. What this does is strip away all of the windows that confine the guest operating system so it seems that the guest operating system is running natively on

the computer. It’s not actually running natively of course. The big giveaway to this is the Windows XP taskbar sitting innocently on top of the GNOME task bar. Outside of that you would think you were running Windows XP.

In the image you can see Internet Explorer and the XP start menu. You can also see Firefox and The GIMP as well as the GNOME panels. It truly is a seamless integration of operating systems that will help to remove confusion from the new user when they are having to work within a virtual machine.

How to do it

Switching back and forth between Seamless and Window’d mode is simple in VirtualBox. But before you can do it you have to install the Guest Additions. Installing Guest Additions is simple: Click the Devices menu (While your Virtual Machine is running) and then select “Install Guest Additions”. You should not have any trouble with this installation. Once it is installed you will have to reboot your guest os. After the reboot is complete you can switch to Seamless Mode by clicking and holding the right Ctrl key and then clicking the “L” key. To get back to Window’d mode you use the same key combination.

Final thoughts

If you haven’t giving the Seamless Mode in VirtualBox a try you should. Seamless mode removes some of the boundaries many users have when trying to work within a virtual machine. As a bonus, VirtualBox is one of the easiest of all the virtualization products available.

What do you think? Have you used VirtualBox’s Seamless Mode? What do you think? Share your experienes with your fellow TechRepublic readers.