From here you can create a new VM by clicking New at the top left. Change
the settings on any currently installed VM by clicking Settings. Start any
installed VM by clicking Start. Delete any VM by clicking Discard. You can
see details of the currently selected VM by clicking Details at the upper right
or your saved snapshots of existing VMs by clicking Snapshots. Everything is
configurable from the GUI. VirtualBox is easy and intuitive to use, even for
novices.
From the GUI, you can clone a machine, export it, and import it on another
machine running VirtualBox. A command-line interface is available for
scripting, focused on VM management activities. You can run VirtualBox
headless and access it by using Remote Display Protocol (RDP). These
activities are beyond the scope of this book but can make VirtualBox a little
more interesting to someone who wants to run VMs remotely (although most
who are going to go through the trouble would probably go ahead and use
KVM and connect to a VM using VNC).
VMware
VMware is an enterprise-focused virtualization platform. The company offers
a limited-feature version that runs on the desktop for free and also sells a full-
featured version. It runs well, is easy to use, and has better features than
VirtualBox. It also requires buying a new license each year, and the license
isn’t cheap. Many people consider VMware’s enterprise server offerings to be
the most powerful and well featured in the business. The VMware software
runs on bare metal; it is the operating system that gets installed on all the
servers in a VMware installation. Then all the resources are controlled from
one central location. VMs can be moved while running from one physical
machine to another in the system with no loss of usability and no downtime.
This can even be done automatically, based on administrator-set criteria, such
as bandwidth, available memory, or processor load. It is also quite expensive
to license. VMware is primarily designed for use by large corporations in
enterprise environments. It deserves a mention here but is not really targeted
toward the same audience as this book.
Xen
Xen is a well-known open source virtualization platform. It is in widespread
use by researchers, hobbyists, developers, and others. Web hosting companies
that offer virtual servers often use Xen. Generally, Xen installs on bare metal,
like VMware. It can be installed on top of another operating system in a