1 Introduction
Innotek VirtualBox is a family of virtual machine products targeting desktop computers, enterprise servers and embedded systems. Due to its modular architecture,VirtualBox can be deployed in any environment where x86 systems are to be virtual-
ized on x86 systems. (With “x86”, we are referring to 32-bit CPUs from AMD and Intelas well as compatible CPUs from other vendors, plus 64-bit CPUs in 32-bit mode.)
1.1 Virtualization basics
With VirtualBox, you can run unmodified operating systems – including all of the software that is installed on them – directly on top of your existing operating system,in a special environment that is called a “virtual machine”. Your physical computer is
then usually called the “host”, while the virtual machine is often called a “guest”.
The following image shows you how VirtualBox, on a Linux host, is running Windows Vista as guest operating system in a virtual machine (displayed in a window on the host):
VirtualBox allows the guest code to run unmodified, directly on the host computer,and the guest operating system “thinks” it’s running on real machine. In the background, however, VirtualBox intercepts certain operations that the guest performs to
make sure that the guest does not interfere with other programs on the host.
• Operating system support. With VirtualBox, one can run software written for one operating system on another (for example, Windows software on Linux) without having to reboot to use it. You can even install in a virtual machine an old operating system such as DOS or OS/2 if your real computer’s hardware is no longer supported.
• Infrastructure consolidation. Virtualization can significantly reduce hardware and electricity costs. The full performance provided by today’s powerful hardware is only rarely really needed, and typical servers have an average load of only a fraction of their theoretical power. So, instead of running many such physical computers that are only partially used, one can pack many virtual machines onto a few powerful hosts and balance the loads between them. With VirtualBox, you can even run virtual machines as mere servers for the VirtualBox Remote Desktop Protocol (VRDP), with full client USB support. This allows for consolidating the desktop machines in an enterprise on just a few RDP servers, while the actual clients will only have to be able to display VRDP data any more.
• Testing and disaster recovery. Once installed, a virtual box and its virtual hard disk can be considered a “container” that can be arbitrarily frozen, woken up, copied, backed up, and transported between hosts. On top of that, with the use of another VirtualBox feature called “snapshots”, one can save a particular state of a virtual machine and revert back to that state, if necessary. This way, one can freely experiment with a computing environment. If something goes wrong (e.g. after installing misbehaving software or infecting the guest with a virus), one can easily switch back to a previous snapshot and avoid the need of frequent backups and restores.
When dealing with virtualization (and also for understanding the following chapters of this documentation), it helps to acquaint oneself with a bit of crucial terminology, especially the following terms:
Host operating system (host OS): the operating system of the physical computer where VirtualBox is running. Also, the host operating system determines which version of VirtualBox is required: VirtualBox for Windows, VirtualBox for Linux
or VirtualBox for Mac
Note: Even though the various VirtualBox versions are usually discussed together in this document, there may be platform-specific differences which we will point out where appropriate.
Guest operating system (guest OS): the operating system that is running inside
the virtual machine. Theoretically, VirtualBox can run any x86 operating system (DOS, Windows, OS/2, FreeBSD, OpenBSD), but to achieve near-native performance of the guest code on your machine, we had to go through a lot
of optimizations that are specific to certain operating systems. So while your favorite operating system may run as a guest, we officially support and optimize for a select few (which, however, include the most common ones).
Virtual machine (VM). When running, a VM is the special environment that VirtualBox creates for your guest operating system. So, in other words, you run your guest operating system “in” a VM. Normally, a VM will be shown as
a window on your computer’s desktop, but depending on which of the various frontends of VirtualBox you use, it can be displayed in full-screen mode or remotely by use of the Remote Desktop Protocol (RDP).
Sometimes we also use the term “virtual machine” in a more abstract way. Internally, VirtualBox thinks of a VM as a set of parameters that determine its operation. These settings are mirrored in the VirtualBox graphical user interface
as well as the VBoxManage command line program; see chapter 8, VBoxManage reference, page 76. They include hardware settings (how much memory the VM should have, what hard disks VirtualBox should virtualize through which
container files, what CD -ROMs are mounted etc.) as well as state information (whether the VM is currently running, saved, its snapshots etc.).
In other words, a VM is also what you can see in its settings dialog.
Guest Additions. With “Guest Additions”, we refer to special software packages that are shipped with VirtualBox. Even though they are part of VirtualBox, they are designed to be installed inside a VM to improve performance of the guest OS
and to add extra features.
1.2 Features overview
Here’s a brief outline of VirtualBox’s main features:
• Clean architecture; unprecedented modularity. VirtualBox has an extremely modular design with well-defined internal programming interfaces and a clean separation of client and server code. This makes it easy to control it from several
interfaces at once: for example, you can start a VM simply by clicking on a button in the VirtualBox graphical user interface and then control that machine from the command line, or even remotely.
Due to its modular architecture, VirtualBox can also expose its full functionality and configurability through a comprehensive software development kit (SDK). Based on the standard technology COM (XPCOM on Linux), this Ap-
plication Programming Interface (API) offers a comfortable way of integrating VirtualBox with other software systems. Internally, VirtualBox uses its own public API, which guarantees that every aspect of the product is accessible to external
customers as well and that all interfaces are well tested.
• Easy portability. VirtualBox runs on Windows 2000, Windows XP and Windows Server 2003 as well as on all major Linux distributions from Red Hat, Novell and others. With VirtualBox 1.4, support for 64-bit Linux and Mac OS X hosts was
added. In addition, a special version for use on embedded µkernel systems is available separately.
• Guest Additions for Windows and Linux. The VirtualBox Guest Additions are packages which can be installed in Windows or Linux guest systems to improve their performance and to provide additional integration and communication with the host system.
– Arbitrary screen resolutions (host-controlled). In guest systems that support it (currently Windows guests), you can change the guest resolution simply by resizing the virtual machine window in the host system.
– Arbitrary screen resolutions (guest-controlled). The VirtualBox Guest Additions can handle arbitrary screen resolutions. Even for guest operating systems for which no Additions have been written yet, VirtualBox will offer
custom VESA resolutions.
• XML configuration store. VirtualBox stores all its configuration in XML files: one XML document for global settings and a XML file per virtual machine. This allows you to transport VM definitions between the different frontends and even
across host computers.
• Great hardware support. Among others, VirtualBox supports:– Full ACPI support. The Advanced Configuration and Power Interface (ACPI) is fully supported by VirtualBox. This eases cloning of PC images from real machines or third-party virtual machines into VirtualBox. With its unique ACPI power status support, VirtualBox can even report to ACPI-
aware guest operating systems the power status of the host. For mobile systems running on battery, the guest can thus enable energy saving and notify the user of the remaining power (e.g. in fullscreen modes).
– I/O APIC support. VirtualBox virtualizes an Input/Output Advanced Programmable Interrupt Controller (I/O APIC) which is found in many modern PC systems. This eases cloning of PC images from real machines or 3rd party virtual machines into VirtualBox.
– USB device support. VirtualBox implements a virtual USB controller and allows you to connect arbitrary USB devices to your virtual machines with out having to install device-specific drivers on the host. USB support is not
limited to certain device categories.
– Multiscreen resolutions. VirtualBox virtual machines support screen resolutions many times that of a physical screen, allowing them to be spread over a large number of screens attached to the host system.
– Built-in iSCSI support. This unique feature allows you to connect a virtual machine directly to an iSCSI storage server without going through the host system. The VM accesses the iSCSI target directly without the extra
overhead that is required for virtualizing hard disks in container files.
– PXE Network boot. The integrated virtual network cards of VirtualBox fully support remote booting via the Preboot Execution Environment (PXE).
• Multigeneration snapshots. VirtualBox can save successive snapshots of the state of the virtual machine. You can revert the virtual machine to the state of any of the snapshots.
• VRDP remote access. You can run any virtual machine in a special VirtualBox program that acts as a server for the VirtualBox Remote Desktop Protocol (VRDP). With this unique feature, VirtualBox provides high-performance remote
access to any virtual machine.
A custom RDP server has been built directly into the virtualization layer and offers unprecedented performance and feature richness.On top of this special capacity, VirtualBox offers you more unique features:
– Extensible RDP authentication. VirtualBox already supports Winlogon on Windows and PAM on Linux for RDP authentication. In addition, it includes an easy-to-use SDK which allows you to create arbitrary interfaces
for other methods of authentication.
– USB over RDP. Via RDP virtual channel support, VirtualBox also allows you to connect arbitrary USB devices locally to a virtual machine which is running remotely on a VirtualBox RDP.
• Folder sharing. VirtualBox folder sharing lets you access files from the host system inside guests. Shared folders can be set up for all virtual machines, or for a single VM. Temporary shared folders may also be set up while a VM is running.
1.3 Operating system support
1.3.1 Supported host operating systems
Currently, VirtualBox is available for the following Windows 32-bit operating systems:
• Windows 2000, service pack 3 and higher
• Windows XP, all service packs
• Windows Server 2003
and for the following Linux 32-bit systems:
• Debian GNU/Linux 3.1 (“sarge”) and 4.0 (“etch”)
• Fedora Core 4 to 7
• Gentoo Linux
• Redhat Enterprise Linux 3, 4 and 5
• SUSE Linux 9 and 10
• Ubuntu 5.10 (“Breezy Badger”), 6.06 (“Dapper Drake”), 6.10 (“Edgy Eft”), 7.04
(“Feisty Fawn”)
Starting with VirtualBox 1.4, the following hosts are also supported:
• 64-bit Linux
• Apple Mac OS X
It should be possible to use VirtualBox on most systems based on Linux kernel 2.4 or 2.6 using either the VirtualBox installer or by doing a manual installation.
1.3.2 Supported guest operating systems
While VirtualBox is designed to provide a generic virtualization environment for x86 systems, our focus is to optimize the product’s performance for a select list of guest systems. The following table provides an overview of current support:
Operating system
Support status
Windows NT
4.0
All versions/editions and service packs are fully supported (but see remark 1 below). Guest Additions are available with a limited feature set.
Windows 2000
/ XP / Server
2003 / Vista
All versions/editions and service packs are fully supported. Guest Additions are available.
DOS / Windows
3.x / 95 / 98 /
ME
Limited testing has been performed. Use beyond legacy installation mechanisms not recommended. No
Guest Additions available.
Linux 2.4 Limited support.
Linux 2.6 All versions/editions and service packs are fully supported (but see remark 2 below). Guest Additions
are available.
FreeBSD Limited support. Guest Additions are not available yet.
OpenBSD Versions 3.7 and 3.8 are supported. Guest Additions are not available yet.
Remarks:
1. With Windows NT 4.0, there are some issues with older service packs. We recommend to install service pack 6a.
2. For Linux 2.6, we strongly recommend using version 2.6.13 or higher for better performance. However, version 2.6.18 (and some 2.6.17 versions) introduced a race condition that can cause boot crashes in VirtualBox; if you must use a kernel
>= 2.6.17, we advise to use 2.6.19 or later.
Screenshots
The screenshots below show several impressions while running VirtualBox on Linux, Windows and some soon-to-be-supported platforms:
 | VirtualBox for Mac OS X, currently in beta test. One virtual machine is running in seamless mode on Leopard. Note the realtime preview of the virtual machine in the dock. |
 | VirtualBox for Mac OS X, currently in beta test. Two virtual machines are visible: one with Windows Vista, another with Gentoo Linux. |
 | Creating a new, empty VM for installing Windows Vista. |
 | The new VM in the VirtualBox main window. Note that an ISO file (containing the Vista setup CD) has been mounted as the VM's CD-ROM drive. |
 | After starting the VM, it boots off the virtual CD-ROM (the ISO file with the Vista setup), and Vista Setup starts up. |
 | Vista is installing into the virtual hard drive. |
 | Vista install complete: the log-on screen. |
 | Compiling VirtualBox on Ubuntu Edgy Eft in VirtualBox on Windows XP. |
 | Details of a snapshot performed after Vista installation. We can revert the virtual machine to this snapshot at a later time. |
 | Damn Small Linux 2.0 works damn well in VirtualBox! |
 | The Virtual Disk Manager allows you to work with VM images. |
 | VirtualBox in Vista inside VirtualBox on XP? Perhaps some day... |
 | A community-based effort is underway to port VirtualBox to OS/2 hosts. This screenshot shows a first alpha version. |
Downloading VirtualBox
For downloading VirtualBox, you will be redirected to the Sun Download Center (SDLC). Make sure you choose the correct platform for your system from the drop down list.
See the changelog for what has changed.
The VirtualBox User Manual is included in the VirtualBox binaries above. If, however, you would like to take a look at it without having to install the whole thing, you can download it in PDF format here:
- User Manual (version 1.6.2, updated 2008-06-06)
You will need a PDF reader such as Adobe Reader to view this file. Most Linux systems will have a PDF reader installed by default.
You may also like to take a look at our frequently asked questions list.
VirtualBox Open Source Edition (OSE)
For a detailed explanation about the differences between VirtualBox and VirtualBox OSE, please take a look at the Editions page. The VirtualBox OSE sources are available free of charge under the terms and conditions of the GNU General Public License, Version 2. By downloading from the below links, you agree to these terms and conditions.
- Checking out from our Subversion server.
svn co http://virtualbox.org/svn/vbox/trunk vbox
After checking out, you should have a look at the build instructions.
Please note that the Open Source Edition does not include an installer or setup utilities, as it is mainly aimed at developers and Linux distributors. We do request that anyone intending to redistribute the Open Source Edition contact us first. Please also take a look at our licensing FAQ, in particular regarding the use of the name VirtualBox.
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