MS Server Virtualization - State of the Software Home

Why Virtualization

Virtual servers provide the capability for creating an internal network; which is a network servicing only the virtual machines. This allows the virtual machines to communicate with one another through a dedicated backbone without having to place packets on the physical network. Virtual servers work just like physical servers when it comes to sending and receiving traffic on the network and purposely applied will have no impact on the network.

However, network performance can suffer if multiple virtual servers share the same physical network adapter. In such cases, the network adapter may cause a bottleneck for the virtual servers. Accordingly, sound planning will call for installing multiple network adapters and setting up the virtual environment in order that each virtual machine gets its own network adapter.

Internal networks are accessible only to virtual machines. Virtual machines, their operating system, and everything else that they contain all exist within a single virtual hard drive file. As with any file, a virtual hard drive file is simple to move from one machine to another. Virtual server software has mechanisms in place to prevent a single virtual server from consuming all of the physical server's resources, this will prevent a single virtual server stealing memory from another. When a virtual machine does not have sufficient resources to run the application, there are configuration choices which can be selected. One option is to reallocate the physical server's resources. Another option is to move the virtual machine to another physical server that is not being as heavily utilized.

Virtual machines are self-contained environments. If a virtual operating system produces a blue-screen error, the crash affects only that virtual machine. The host operating system and any other virtual machines that may be running are all isolated from the crash. However, virtual machines are dependent on the host operating system. If the host operating system crashes, every virtual machine on the server will also fail.

Virtualization and consolidation of servers and applications across a network can yield significant bottom line advantages: reduction in hardware, facility and energy costs, and reduced carbon footprint. Given the ongoing evolution of hardware, operational challenges in information technology, and the underlying economics, there are compelling reasons to expect this trend in server virtualization to continue. Implementing virtual servers can also help in streamlining and simplifying the backup process. Virtual servers make use of a virtual hard drive, which is a file residing on the host machine. This affords the capability to back up the virtual machine in less time and with less effort than is usually involved in backing up a physical server.

Windows Server 2008 R2 has built in Hyper-V for virtualizing system resources without the cost of third-party software and Live Migration to move virtual machines with minimal downtime. Microsoft SQL Server 2008 can be used for consolidating database servers to create virtual data centers which reduce hardware and administrative expenses. Microsoft System Center handles virtual and physical environments across multiple operating systems like Windows, Linux and UNIX, and provides unified control.

Microsoft System Center
Server consolidation is important for realizing cost savings and benefits associated with an effective virtualization strategy.  MS System Center provides the capability to simplify, automate, and accelerate a server consolidation strategy. MS System Center supports Microsoft Hyper-V, Microsoft Virtual Server, and VMware ESX Server.  It also aligns with process frameworks.  MS System Center has been designed to start a new server consolidation project, fit into an existing virtualization strategy, and help consolidate servers into a Microsoft-based virtualization technology.

MS System Server collects information for:

1 - Identifying candidates for server virtualization.

2 - Validating candidates for virtualization hosts.

3 - Assigning guest systems to virtualization hosts.

4 - Simplifying virtualization management.

This information can then be used by IT management to identify systems that should be virtualized; servers which are underutilized and ideal candidates to act as virtual hosts; place virtualized guest servers for optimal performance.

MS System Center delivers the capability to streamline and simplify the planning, implementation, and subsequent management of server consolidation projects.  System Center provides informed guidance on selecting systems to be virtualization hosts, or guest systems.  The Virtualization Candidates report identifies which physical servers should be transitioned to virtual systems.

The data provided includes:

• Historical performance data, such as CPU, memory, and disk usage.

• Server configuration, including the number of processors, RAM, etc.

Virtualization host server candidates can be identified using System Center reports that show system memory, CPU, and disk utilization over time.  System Center automates the P2V: physical-to-virtual and V2V: virtual-to-virtual system conversion processes.

• P2V conversions support is provided for Windows Server 2008, Windows Server 2003, and Windows 2000 Server System Center provides the following benefits:

• V2V conversions enables host-to-host migrations or transitions to a common Microsoft virtualization technology.

MS PowerShell integration enables a scripted approach to machine consolidation which improves the ability to integrate and automate with other processes or solutions. MS PowerShell is a command-line shell and scripting language for performing system administration tasks on MS Windows operating systems and the applications that run on the MS Windows operating system. Built on the Microsoft .NET Framework, command tools, known as cmdlets, provide the ability to manage the computers in an enterprise from the command line. MS Windows PowerShell provides access to data stores, such as the registry and the certificate store. Windows PowerShell also has full support for all WMI: Windows Management Instrumentation classes.

System Center can be used to determine where to base a virtual machine, using built-in calculations and user- selectable preferences.  The Virtual Machine Deployment wizard uses information collected by System Center on the environment to calculate and recommend the most suitable virtualization hosts for a guest system.  There are adjustable virtualization host selection prioritizations which enables users to set system-wide placement settings to weight virtualization host selection, focusing on load balancing and resource maximization.

System Center also has the ability to:

• Re-weight the importance of resources for virtualized guest systems.

• Create a shared data SAN storage pool which can be simultaneously accessed by all physical and logical servers and workloads.

After server consolidation projects are complete, the System Center helps in managing the health and performance of the systems.

Given the evolution of hardware, operational challenges in information technology, and the underlying economics, there are compelling reasons to expect this trend in server virtualization to continue. In SYS-ED internetworking courses, SYS-ED offers clients the option of having demonstrations and supplemental exercises with Microsoft virtualization software.