Sun Microsystems' xVM VirtualBox desktop virtualization software is an increasingly powerful, no-cost alternative to VMware Workstation and Parallels Desktop products and should be added to the consideration shortlist of software developers and IT managers.
Any IT professional who wants to get more familiar with virtualization technology that goes beyond a 30-day trial version provided by competitors should get a hold of Virtual Box.
I tested VirtualBox version 2.1, a Dec. 17, 2008, maintenance release that added important new features to the product that make it even more useful for IT shops that also use VMware. VirtualBox 2.1 now has full support for VMware VMDK and Microsoft VHD hard drive image files, including making snapshots. VirtualBox 2.1 also added support for hardware virtualization provided by Intel and Advanced Micro Devices chips running on Mac OS X physical hosts. I conducted my tests on a Mac Mini with 2GB of RAM and an Intel Core 2 Duo processor.
While VirtualBox is an open-source project, it is backed and promoted by Sun, making the project a viable choice for IT managers who must show that support options are available for a tool before bringing it into the test-and-development or production environment.
VirtualBox Evolves Under Sun
The guest operating system uses files that represent the hard drive. Under normal circumstances, VMs created in VirtualBox use VDI files for the virtual hard drive. Using VirtualBox 2.1, I was able to use virtual hard drive files from VMware (VMDK files) and Microsoft (VHD files), which the VirtualBox VMs recognized as useable drives. The ability to share hard drives across virtualization platforms is an important step in bringing VirtualBox into more useful and direct competition with VMware's Workstation product, the current gold standard of this product class.
Along with ongoing support and a commitment to future product development, the VirtualBox 2.1 added new features to entice developers. For those using 64-bit hardware, it is now possible to run 64-bit guests on 32-bit host operating systems-a feature that is listed as experimental for the time being. Sun officials said the experimental label will be lifted after sufficient feedback has been gathered from testing.
I tried this successfully on a PC built using an AMD chip, which was loaded with 8GB RAM and running Windows XP SP3. I created several VMs that ran the 64-bit version of Windows Server 2003 with no problems running the OS or 64-bit applications, including Microsoft SQL Server 2005. The more likely use of this feature is with Linux OSes and applications that have sophisticated graphical interfaces for 32-bit versions, but are command-line only in their 64-bit incarnation.
VirtualBox is a Type 2 hypervisor, which means that it is software that installs on top of the operating system installed on the physical host. Type 2 hypervisors typically are somewhat slower than Type 1 hypervisors that interface directly with physical hardware. VirtualBox 2.1 partially overcomes this limitation by creating direct hardware access for some operations.
At MacWorld in San Francisco, I saw a demonstration of experimental support for applications that use 3D features through OpenGL. The functionality is provided through the VirtualBox Guest Additions and works only on hardware that provides hardware graphics acceleration. In the demonstration I saw, the Google Earth globe spun freely, with very little hesitation. The application was running on a Windows XP VM running on a MacBook Pro.
Labs Technical Director Cameron Sturdevant can be reached at email@example.com