VirtualBox 2.0.4_OSE running Fedora 10 on Ubuntu 8.10
|Initial release||January 15, 2007|
|Stable release||(February 12, 2010 ) [+/−]|
|Preview release||(N/A) [+/−]|
|Written in||C++, C, X86 assembly|
|License||Proprietary / GNU General Public License (Optionally CDDL for most files of the source distribution)|
Oracle VM VirtualBox is an x86 virtualization software package, originally created by German software company Innotek, now developed by Oracle Corporation as part of its family of virtualization products. It is installed on an existing host operating system; within this application, additional guest operating systems, each known as a Guest OS, can be loaded and run, each with its own virtual environment.
Supported host operating systems include Linux, Mac OS X, OS/2 Warp, Windows XP, Windows Vista, Windows 7 and Solaris; there is also an experimental port to FreeBSD. Supported guest operating systems include a small number of versions of NetBSD and various versions of DragonFlyBSD, FreeBSD, Linux, OpenBSD, OS/2 Warp, Windows, Solaris, Haiku, Syllable, ReactOS and SkyOS.
According to a 2007 survey by DesktopLinux.com, VirtualBox was the third most popular software package for running Windows programs on Linux desktops.
The application was initially offered under a proprietary software license. One version of the product was available at no cost for personal or evaluation use, subject to the VirtualBox Personal Use and Evaluation License (PUEL). In January 2007, VirtualBox OSE (Open Source Edition) was released as free software, subject to the requirements of the GNU General Public License (GPL), version 2.
The original developer, innotek, also contributed to the development of OS/2 and Linux support in virtualization and OS/2 ports of products from Connectix which were later acquired by Microsoft. Specifically, innotek developed the “additions” code in both Microsoft Virtual PC and Microsoft Virtual Server, which greatly improves host-guest OS interactions. OS/2 has been notoriously difficult to run virtualized in the past due to extensive ring 2 execution.
There are two versions of the VirtualBox software.
The full VirtualBox package comes under a proprietary Personal Use and Evaluation License (PUEL), which allows using the software free of charge for personal and educational use and evaluation of the product. Licenses for commercial deployment of the full VirtualBox package can be purchased from Oracle, although commercial use by individuals within a company is covered by the free PUEL.
Several guest operating systems can be loaded. Each can be started, paused and stopped independently. The host operating system and guest operating systems can communicate with each other, through a common clipboard or using the network facility provided, as can guest operating systems if more than one is running.
Hard disks are emulated in a special container format called "Virtual Disk Images", which is incompatible with the formats used by other virtualization solutions. These are normally stored as system files on the host operating system (with a .vdi suffix). Alternatively, VirtualBox has a unique feature in that it can connect to iSCSI targets and use them as virtual hard disks as well. VirtualBox can also read and write disk images in VMware Virtual Machine Disk Format (VMDK) and Microsoft Virtual PC VHD format. This means that a VirtualBox virtual machine can be set up using disks that were created in VMware or Microsoft Virtual PC.
ISO images can be mounted as CD/DVD drives. For example the DVD image of a Linux distribution can be downloaded and used directly by VirtualBox. While there is no need to burn a disk, it is also possible to mount physical CD/DVD disks directly to a virtual machine.
By default VirtualBox provides graphics support through a custom virtual graphics card which is VESA compatible. With the Guest Additions for Windows, Linux, Solaris or OS/2 guests comes a special video driver that allows for better performance and features such as dynamically adjusting the guest resolution when the VM window is resized.
For an Ethernet network adapter, VirtualBox virtualizes these Network Interface Cards: AMD PCnet PCI II (Am79C970A), AMD PCnet-Fast III (Am79C973), Intel Pro/1000 MT Desktop (82540EM), Intel Pro/1000 MT Server (82545EM), and Intel Pro/1000 T Server (82543GC). Such a broad range of the emulated network cards allows running many operating systems without finding and installing drivers. By default, VirtualBox sets the network up with NAT through which user programs like Firefox or ssh can operate. For hosts other than Windows Vista, other options exist, such as virtual networks between guests. Up to eight network adapters can be attached simultaneously, but only four are configurable through the graphical interface.
For a sound card, VirtualBox virtualizes an Intel ICH AC'97 device or a SoundBlaster 16 card.
In the "full release" (not in the open-source edition), a USB controller is emulated (both USB 1.1 and USB 2.0) so that any USB devices attached to the host can be seen in the guest. If VirtualBox acts as an RDP server, it can also use USB devices on the remote RDP client as if they were connected to the host.
VirtualBox attempts to run as much guest code natively (that is, directly on the host processor) as possible. This works well for user-mode code running in the guest's ring 3 of the Intel ring architecture. However, the guest's ring-0 code, which will usually contain many privileged instructions, will need to be intercepted. VirtualBox has a rather novel approach to fix this conflict: It tricks the guest operating system to actually execute its ring-0 code in ring 1, which is normally unused on the Intel architecture.
If problems arise, VirtualBox has a built-in dynamic recompiler, like other virtualizers do. VirtualBox's recompiler is based on the free and open-source QEMU. In addition, however, VirtualBox automatically disassembles and, in many situations, patches the guest code to avoid future recompilations, as these are relatively expensive. As a result, both the guest's ring-3 and ring-0 code can run natively most of the time, and with this combination of "traditional" recompiling and actual code patching, VirtualBox achieves a performance that is comparable to that of VMware.
Only available in the full (closed source) version:
A Google Code project called VirtualBox Web Console re-implements the VirtualBox UI using AJAX, allowing users to administer VirtualBox remotely from a web browser. It is released under the MIT License.
A roadmap of features which are planned to be added to VirtualBox was released at the CommunityOne 2008 conference. A second roadmap was disclosed at the Open Source Conference in Malta. The roadmaps included:
Virtual desktop infrastructure (VDI) is the server computing model enabling desktop virtualization but Virtual Desktop Image (VDI) is also the name of the default VirtualBox container storage format.
While VirtualBox is usually considered a desktop virtualization product, Sun has decided to use it for its desktop virtualization product Sun VDI. This product uses a customized version of VirtualBox that is integrated into the Virtual Desktop Infrastructure environment using VirtualBox webservices.
Virtual Desktop Image (VDI) is the name of the default storage format for VirtualBox containers.
VirtualBox's command-line utility VBoxManage includes options for cloning disks and importing and exporting file systems, however, it does not include a tool for increasing the size of the filesystem within a VDI container as this can be achieved in many ways with third-party tools or the guest OS itself.