VirtualBox is a cross-platform virtualization application. What does that mean? Secondly, it extends the capabilities of your existing computer so that it can run multiple operating systems inside multiple virtual machines at the same time. So, for example, you can run Windows and Linux on your Mac, run Windows Server on your Linux server, run Linux on your Windows PC, and so on, all alongside your existing applications. You can install and run as many virtual machines as you like -- the only practical limits are disk space and memory.
VirtualBox is deceptively simple yet also very powerful. It can run everywhere from small embedded systems or desktop class machines all the way up to datacenter deployments and even Cloud environments.
The following screenshot shows you how VirtualBox, installed on a Mac computer, is running Windows 8 in a virtual machine window:. In this User Manual, we'll begin simply with a quick introduction to virtualization and how to get your first virtual machine running with the easy-to-use VirtualBox graphical user interface. Subsequent chapters will go into much more detail covering more powerful tools and features, but fortunately, it is not necessary to read the entire User Manual before you can use VirtualBox.
Running multiple operating systems simultaneously. VirtualBox allows you to run more than one operating system at a time. This way, you can run software written for one operating system on another for example, Windows software on Linux or a Mac without having to reboot to use it. Software vendors can use virtual machines to ship entire software configurations.
example, installing a complete mail server Multi display cloning disabled dating on a real machine can be a tedious task. With VirtualBox, such a complex setup then often called an "appliance" can be packed into a virtual machine. Installing and running a mail server becomes as easy as importing such an appliance into VirtualBox.
Testing and disaster recovery. Once installed, a virtual machine and its virtual hard disks 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. Any number of snapshots can be created, allowing you to travel back and forward in virtual machine time. You can delete snapshots while a VM is running to reclaim disk space. Virtualization can significantly reduce hardware and electricity costs. Most of Multi display cloning disabled dating time, computers today only use a fraction of their potential power and run with low average system loads.
A lot of hardware resources as well as electricity is thereby wasted. 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. When dealing with virtualization and also for understanding the following chapters of this documentationit helps to acquaint oneself with a bit of crucial terminology, especially the following terms:.
This is the operating system of the physical computer on which VirtualBox was installed. Most of the time, this User Manual discusses all VirtualBox versions together.
There may be platform-specific differences which we will point out where appropriate. This is the operating system that is running inside the virtual machine. 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.
This is the special environment that VirtualBox for your guest operating system while it is running.
In other words, you run your guest operating system "in" a VM. Normally, a VM will Multi display cloning disabled dating 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 Multi display cloning disabled dating full screen mode or remotely on another computer.
In a more abstract way, internally, VirtualBox thinks of a VM as a set of parameters that determine its behavior. They include hardware settings how much memory the VM should have, what hard disks VirtualBox should virtualize through which container files, what CDs are mounted etc. In other words, a VM is also what you can see in its settings dialog.
This refers to special software packages which are shipped with VirtualBox but designed to be installed inside a VM to improve performance of the guest OS and to add extra features. VirtualBox is a so-called "hosted" hypervisor sometimes referred to as a "type 2" hypervisor.
Whereas a "bare-metal" or "type 1" hypervisor would run directly on the hardware, VirtualBox requires an existing operating system to be installed. It can thus run alongside existing applications on that host. To a very large degree, VirtualBox is functionally identical on all of the host platforms, and the same file and image formats are used. This allows you to run virtual machines created on one host on another host with a different host operating system; for example, you can create a virtual machine on Windows and then run it under Linux.
You can even import OVFs that were created with a different virtualization software. No hardware virtualization required. As opposed to many other virtualization solutions, you can therefore use VirtualBox even on older hardware where these features are not present. The VirtualBox Guest Additions are software packages which can be installed inside of supported guest systems to Multi display cloning disabled dating their performance and to provide additional integration and communication with the host system.
After installing the Guest Additions, a virtual machine will support automatic adjustment of video resolutions, seamless windows, accelerated 3D graphics and more. In particular, Guest Additions provide for "shared folders", which let you access files from the host system from within a guest machine. Among others, VirtualBox supports:. VirtualBox can present up to 32 virtual CPUs to each virtual machine, irrespective of how many CPU cores are physically present on your host.
VirtualBox implements a virtual USB controller and allows you to connect arbitrary USB devices to your virtual machines without having to install device-specific drivers on the host. USB support is not limited to certain device categories. VirtualBox virtualizes a vast array of virtual devices, among them many devices that are typically provided by other virtualization platforms.
This Multi display cloning disabled dating cloning of PC images from real machines and importing of third-party virtual machines into VirtualBox.
This eases cloning of PC images from real machines or third-party virtual machines into VirtualBox. For mobile systems running on battery, the guest can thus enable energy saving and notify the user of the remaining power e.
VirtualBox virtual machines support screen resolutions many times that of a physical
Multi display cloning disabled dating, allowing them to be spread over a large number of screens attached to the host system. 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.
VirtualBox can save arbitrary snapshots of the state of the virtual machine. You can go back in time and revert the virtual machine to any such snapshot and start an alternative VM configuration from there, effectively creating a whole snapshot tree.