To Grasp the Cloud—Fundamental Concepts - Deploying and Managing a Cloud Infrastructure - page 39

VirtualBox (Open Source)
VirtualBox is primarily used in the desktop virtualization market where it supports all the
major server operating systems, including Sun Solaris, Mac OS X, Microsoft Windows, and
Linux. VirtualBox was acquired by Sun Microsystems, which has continued development of the
platform and kept it open source. In 2010, Sun became part of Oracle, and now VirtualBox is
part of Oracle.
Citrix XenServer (Proprietary)
XenServer emerged from the Xen Project, which was open source. This is one of the primary
reasons Citrix has kept the core XenServer offering free of charge. More advanced, feature-
laden variants of XenServer are sold as regular commercial software with added functionality
for better management, automation, and availability. Just like Xen Project, XenServer is tightly
integrated into Linux itself, enabling native-like disk, network, and processor performance.
Citrix XenServer ships in several editions with variants of the following functionality:
XenCenter Management Console The management console is available in all
editions, including the free core edition. The management console can be used to
manage a virtual server.
High Availability (HA) This feature is a must-have for enterprise virtual server deployments,
especially in private cloud deployments.
Distributed Virtual Switch (DVS) DVS provides network-switching flexibility when network-
ing is implemented in a virtualized data center. It provides cloud network administrators with
fine-grained control over switching stack layout. The granular control provides greater visibil-
ity into the network traffic pattern, and the Distributed Virtual Switch Controller (DVSC) can
be used to fine-tune vSwitch settings or increase network security.
Power Management Essential as well as elaborate power management functionality is
available for administrators within the management console.
System Monitoring and Alerts Administrators can configure event-based alerts.
Live Storage Migration This feature is available in paid editions and lets users migrate
their data into XenServer from another deployment without disrupting service.
VMware vSphere/ESXi (Proprietary)
VMware leads the overall server virtualization market with its enterprise-grade vSphere
and ESXi server virtualization offerings. The vSphere and bundled ESXi are available in
six variants, starting with one free edition and including five commercial editions. vSphere
is a suite of components and modules that are collectively called the vSphere server.
VMware ESXi is a Type 1 hypervisor that ships with its own variant of Linux kernel
module that is called the VMkernel and loads all other modules. Since it's a bare metal
hypervisor, it does not require an OS on the host server and can support various guests,