Server virtualization technologies for x86-based HP BladeSystem and HP ProLiant servers, 3rd edition

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Abstract
Virtual machine technology is the most widely understood and adopted form of server virtualization
technology today. It is a powerful technology that can reduce overall costs, decrease power
consumption, footprint requirements, and improve resource utilization. This technology brief describes
how HP is using virtual machine technology and expanding into other areas of server virtualization
such as physical-layer abstraction and management technologies for virtualization. These include
ProLiant iVirtualization, HP Virtual Connect, logical servers, and HP Insight Dynamics – VSE. This
technology brief is written with the assumption that readers understand the basics of virtual machine
technology.
Introduction
The term server virtualization refers to abstracting, or masking, a physical server resource to make it
appear different logically to what it is physically. In addition, server virtualization includes the ability
for an administrator to relocate and adjust the machine workload. In its broadest sense, server
virtualization refers to techniques implemented using either software or hardware. However, the term
server virtualization is commonly used as a synonym for virtual machine technology, because that is
the most widely adopted form of server virtualization technology today for x86-based servers. To
avoid confusion, this technology brief uses the term machine abstraction to refer to the broad set of
technologies that abstract an entire physical server and allow its resources to be pooled and shared.
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Machine abstraction logically abstracts and isolates the operating system (OS) and application
workload from the underlying hardware, and can be implemented using software or hardware
techniques.
Machine abstraction technology is important because as more server resources are abstracted, the IT
organization can become more efficient and effective:
Reduces total cost of ownership as physical resources are used to their full potential
Increases flexibility because resources can be provisioned or moved as needed
Increases scalability because resources can be scaled up or down based on changing workload
demands
Improves resiliency by simplifying backup, failover, and disaster recovery solutions
Machine abstraction can be performed in the software layer (virtual machines), or physical layer. HP
introduced physical-layer abstraction with HP Virtual Connect, which abstracts the server-to-network
connections. HP also introduced the concept of logical servers, allowing administrators to establish
server profiles, or containers, to describe an abstracted server. Figure 1 indicates the locations where
logical servers can be landed:
Pool of servers such as a BladeSystem Virtual Connect domain (referred to as a physical
machine-logical server, PM-LS)
Hypervisor-based virtual machine (referred to as a virtual machine-logical server, VM-LS)
Figure 1 also shows a centralized management server (CMS) as the top-level orchestration manager
for the data center. Using a CMS, server administrators have a single console and server
management tool that spans multiple physical machines, gives a comprehensive view of the server
infrastructure, and can act as a ―collection‖ tool for all the machine abstractions (physical-layer or
software-layer). Figure 1 shows HP Insight Dynamics – VSE as an example of a CMS.
HP is bringing Virtual Connect, virtual machine, and integrated management technologies together so
IT administrators can create and manage virtual machines and physical machines in the same manner
throughout the lifecycle of a server. The following sections discuss each of these technologies.
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Sharing may be done concurrently or sequentially.