Virtualization programs allow users to launch or install a foreign system within a software environment. One of the most popular of these programs is VirtualBox, which is free for personal use. A major update of VirtualBox to version 5 was released in June.

Virtualization solutions have been put to a variety of uses. Deployed on servers, they cleanly isolate services and ensure uniform load balancing between hardware resources. On desktops, they provide a convenient solution for testing or using other systems. Linux users in particular frequently rely on them to work with the occasional, indispensable Windows application.

Since 2005, VirtualBox [1] has vied for the attention of the customers and competed with commercial offerings from VMware [2] and Parallels [3]. The project, which was acquired by Sun Microsystems in 2008 and, in turn, by Oracle in 2010, has now published a major release: version 5. I put VirtualBox through its paces to see what's new or different.

For this article, I mainly used Windows 7 as the guest system; Ubuntu 15.04 was also tested to verify a number of aspects. The test environments comprised a 64-bit version of openSUSE 13.2 with the latest patches and 64-bit Ubuntu 15.04. The CPU was an Intel Core i5 with four cores running at a clock speed of 3.2GHz and supported by 8GB of DDR3 RAM. The graphics adapter was a Radeon HD5670.

Installation

Oracle offers a free download of VirtualBox [4]. The open source and GPL-licensed core application lacks a couple of functions, such as USB support, which the company provides in the form of a proprietary – but also free – extension pack. Oracle offers packages in RPM and DEB format for around a dozen Linux systems. If you can't find a package for your flavor of Linux, you can choose the generic variant with the .run suffix. In our lab, the software did not have any additional dependencies during the installation and was easy to set up. Because the setup proceeds to compile the required kernel modules directly, you will need typical developer programs such as make and gcc for this step.

To install the extension pack, first launch the application and then click on File | Preferences. In the Settings dialog, change to Extensions, and press the square button with the down arrow to launch the file manager, from which you can select the downloaded extension pack. The software is flexible in terms of guest systems and supports practically any popular operating system – from Linux in a variety of flavors through Windows NT 4.0 to 10, to Mac OS X. Even more exotic operating systems, such as Solaris, IBM OS/2, and the various BSD flavors, are no problem for VirtualBox as well.

Configuration

VirtualBox distinguishes between global and local configurations. Global configs apply to all virtual machines across the board, whereas local configs only define the settings for an individual machine. You can access the global setup in VirtualBox's main window below File | Preferences (Figure 1). In the General tab, you primarily want to define the default storage location for your virtual machines.

Figure 1: In the global configuration, you define settings that apply to all virtual machines.

The Input tab displays the configuration settings for keyboard shortcuts. VirtualBox can largely be controlled by keyboard shortcuts. The most important shortcuts use the Host key, which you can access in the Virtual Machine tab. In the default setting, the Host key is the right Control key, which you can use in combination with other keys. For example, Host+I detaches the mouse pointer from the guest, and Host+F switches to full-screen mode. In contrast to older versions, you can also use the familiar Ctrl+Alt sequences familiar to users moving from VMware.

Another aspect that is quite important is the global display resolution, which you can see in the Display tab. If you set this to a specific value, you will see that dynamic resizing and full-screen mode do not work in your virtual machines. For this reason, you will want to define Automatic as the Maximum Guest Screen Size.

Windows 7

Because Windows 7 is still the most popular system from Redmond, I focus on its use as a guest. After creating a virtual machine, you need to make a number of changes to the local settings. Start by clicking on the Settings icon and selecting the Advanced tab below General. If you want to share the clipboard with the host system, the choices for the Shared Clipboard drop-down are Host To Guest, Guest To Host, or Bidirectional. The same choices are available for the Drag'n'Drop drop-down.

New in version 5, you can protect your virtual machine against unauthorized access; navigate to the Encryption tab, also in the General tab, and select Enable Encryption. In the drop-down menu, you can choose between AES-128 and AES-256 encryption methods. After entering the user password, VirtualBox will encrypt the container or the virtual disk. Incidentally, this also works for existing virtual machines, although the conversion can take a couple of minutes to complete depending on the virtual machine's size. Encryption can just as easily be removed by unchecking the Enable Encryption box and then typing the password.

In the default setting, VirtualBox disables 2D/3D acceleration, which will particularly affect multimedia applications. To enable acceleration, change to Display and check the appropriate boxes (Figure 2). Additionally, you can define the graphic memory size in this dialog; you will want to assign a least 64MB.

Figure 2: In the guest settings, you can define the behavior and hardware environment of the virtual machine in detail.

The USB tab takes you to the configuration for the USB stack and the connected devices. In my experience with Windows, this feature only works correctly if the virtual interfaces match the physical hardware. For example, if you enable a USB 3.0 (xHCI) Controller but your computer only has a USB 2.0 interface, Windows will not find any drivers. Strangely, this only applies to Windows: Ubuntu detected the USB memory stick with different settings without any problems.

VirtualBox takes about 20 minutes to install Windows 7 Home Premium on the virtual machine from an ISO image stored on the hard disk; this is approximately the duration of a normal set up. What was far more difficult was the task of automatically installing updates, which took several hours in our lab; moreover, various packages failed to install. However, I can't say whether the virtual machine was actually responsible for this.

The guest extensions in VirtualBox mainly integrate additional drivers designed, on the one hand, to accelerate the system and, on the other, to enable additional functionality, such as dynamic display resizing. To set this up, select Devices | Insert Guest Additions CD image from the menu of the running virtual machine. This causes VirtualBox to mount an ISO image with the extensions at the DVD port and thus provide it to the machine. Be aware of a special feature here: Windows installs all the extensions without any trouble – with the exception of 3D support. Because you will definitely want this feature, prepare for a detour to safe mode.

To install 3D, restart the virtual machine and press F6 followed by F8 before bootup. From the boot menu, select Safe Mode and press Enter to confirm. When installing the guest extensions, the software offers to install WDDM drivers configured for Windows Aero; however, they are still experimental. Alternatively, you can set up standard Direct3D support (Figure 3).

Figure 3: Although the guest extensions installer offers WDDM drivers, it classifies them as experimental. I advise against using them.

In our lab, the Direct3D variant turned out to be far superior. Although the internal Windows benchmark told us that the system with the WDDM drivers had far better performance, it turned out to be more jerky and far slower under practical conditions than with the Direct3D drivers. This impression was also confirmed by the browser benchmark, Peacekeeper [5], which I ran on Google Chrome. The values dropped by about half with WDDM.

As a general rule, you will want to install updates and service packs before installing the guest extensions, because service packs seem to remove, or at least disable, the extensions. After the installation, you will see a small icon in the system tray. In contrast to VMware, the icon only reminds you of the fact that the extensions are in place and does not offer any functionality. In the Start menu, you will only find a link for uninstalling the extensions, but no configuration options.