Virtualization Shootout: VMware Server vs. VirtualBox vs. KVM
VirtualBox is a relative newcomer to the virtualization market, with its initial release in early 2007. VirtualBox originally was created by Innotek, but it has since been acquired by Sun Microsystems. Version 3.0 of the software was released recently and includes many new features.
Ease of Installation
VirtualBox ships for Linux hosts as a native package for most distributions. There are packages for Ubuntu, Debian, OpenSUSE, Fedora, Mandriva, Red Hat, Turbolinux and PCLinuxOS 2007. Installing the software is as simple as downloading the package for your OS, then using your native package manager to install the package. On Ubuntu 9.04, the binary package is 43MB, and installation required the additional packages of libcurl3, libqt4-network, libqtcore4, libqtgui4 and python2.5, all of which are easily fetched via apt-get. Double-clicking on the package in Nautilus launches the Ubuntu Package Installer, which pulls in the dependencies automagically. In all, installation is straightforward, quick and easy. VirtualBox also maintains a repository for Debian-based distributions that you can add to your apt sources. Then you simply can apt-get the package (virtualbox-3.0) and its dependencies.
Ease of installation score: 3. The only way VirtualBox could be easier to install is if it were included in the Ubuntu apt sources out of the box.
VirtualBox includes a native “fat client” for your host OS that allows you to manage your virtual machines (Figure 3). The client is easy to use, and it's wizard-based—much like the VMware admin console. Creating virtual machines is a snap, and VirtualBox gets kudos for making it as easy as VMware to spin up new virtual machines.
If you want to run your guest machines in headless mode, VirtualBox has that covered too. There is a VBoxHeadless management binary that will bypass the admin GUI and start an RDP server running for that particular VM. Once your VM is running in headless mode, you can point an RDP client to your physical host's port 3389 (by default, the port is also configurable), and you'll see the virtual machine's console. This is very handy if you're not at the physical machine or can't tunnel X easily. Figure 4 shows a VM running with VirtualBox.
Administrative tools score: 3. VirtualBox includes excellent tools for creating and managing virtual machines. The fact that it's a native “fat client” rather than a Web GUI is slightly less convenient for multiplatform access, as compared to VMware, but every bit of functionality is there and easy to use.
VirtualBox may be a young project, but it certainly doesn't lack features. It compares with VMware handily in many areas, such as the following:
Support for bridged, NAT and host-only networking.
Two-processor virtualized SMP.
64-bit support for both hosts and guests.
Snapshot capability for easy capture and rollback.
Unlike VMware, VirtualBox is available in both a proprietary and open-source edition. The open-source edition is released under GPL, but it doesn't include the following features that are available only in the proprietary version:
The headless RDP server is not available in the open-source edition.
There is no virtualized USB support in the open-source edition.
Because USB and RDP support aren't included, the proprietary version's USB-over-RDP feature isn't in the open-source edition.
The virtualized serial ATA disk controller isn't in the open-source edition. Disks appear as either SCSI or IDE devices.
Capabilities score: 3. VirtualBox nearly matches VMware Server feature for feature.
As mentioned above, VirtualBox ships two different versions of its product: a proprietary version and an open-source edition. The proprietary version is licensed under the VirtualBox Personal Use and Evaluation License (PUEL), and although you are asked to register the software when it's first launched, it's not required. The open-source edition is covered under the GPL, and it's truly open source, though it does omit the four features I mentioned previously. If you do decide to run the open-source edition, be advised that it doesn't come as a binary package, only source code, so you will have to build it yourself. Building it yourself isn't terribly painful, as the folks at VirtualBox have supplied fairly good instructions.
Licensing score: 2. VirtualBox's PUEL license on the more feature-rich version isn't open source, but VirtualBox does make most of the source code available and provides instructions on how to build the code if you don't want to succumb to the evils of proprietary licensing.
VirtualBox total score: 11.
Bill Childers is the Virtual Editor for Linux Journal. No one really knows what that means.