Note: This post is mostly a “note to self”, but I thought that others might also benefit from this information too.

Lately I’ve been using VirtualBox to test out various Linux distros, and to re-familiarize myself with the otherwise less familiar… Having rooted myself for some time now in Debian-based systems, I thought that it would be fun to revisit RPM-based distros by experimenting with CentOS, and I’ve also been enjoying Arch Linux quite a bit lately (note: if you’re not familiar with Arch, check out the “Arch Way” to see if it fits with your computing philosophies…). Additionally, with the arrival the latest CrunchBang Linux (v.10) (#!), previously a Ubuntu-based system that has migrated to Debian with this latest version – I’ve been really enjoying the latest release of #! and have been interested in learning about how it differs from previous releases.

Although a great tool, one of the issues with using VirtualBox is that the default screen size is so small. To enlarge the screen size of your VirtualBox session, try doing the following:

-==[ FIRST ]==-
On the virtual console, click the Devices drop down, and then select Install Guest Addons.  This will mount a virtual CD within your virtual session.  You may get an error at this step but just hit Ok and it should likely work.  Now you should see a CD icon on your desktop or in your file manager.

-==[ SECOND ]==-
Open up your Terminal and type:

$ cd /media/cdrom0

EDIT – In newer version of VirtualBox, you may see a directory listed in /media that represents GuestAdditions; it may be called something similar to “VBOXADDITIONS_3.2.8_64453”, in which case, you would cd to that directory instead of /media/cdrom0 as indicated above.

In this folder there are some scripts for 64 bit linux and 32 bit.  If you find that the 64bit files do not work properly, you may have to use the 32 bit version within 64 bit linux.  On my 32 bit system, I’ll go back to my terminal and type:

$ sudo sh ./VBoxLinuxAdditions-x86.run

-==[ THIRD ]==-
This will configure your virtual session so that it can allow you to use higher resolutions. First you must reboot your virtual session or restart the display manager by hitting Ctrl+Alt+Backspace (the latter works depending on your host Linux distribution…).

-==[ FOURTH ]==-
Using your tool of choice in the guest operating system, set the screen resolution for your guest OS and the session window should resize.

Screenshot: CentOS and CrunchBang v.10 running in VirtualBox on Ubuntu 9.04 host:

Source: http://www.fettesps.com/virtualbox-increasing-your-screen-resolution/