- Internet & the Web
IT Virtualization - Hyper-V Part 1
Virtual Servers, Networks, and Clients
One of the hottest topics in network administration today is virtualization. Virtualization is also another option in server implementation by using virtual computers. Virtualization can allow a network administrator to host entire operating systems or multiple applications on a single server or on a cluster of servers. While reducing the carbon footprint on the environment by eliminating the space and storage need for multiple physical server and the electricity needed to power them.
Another benefit to many business organizations is lowered cost and overhead.
By using virtualization a network administrator also provides a stronger level of security to the network in general since each virtual environment is isolated from the others. While there are many offerings in virtualization software applications available today, I will stick to Microsoft Hyper V in this discussion. The reason being that the while there are many flavors to choose from the concepts of virtualization remain the same, and the scope to big to encompass in this discussion without boring you to tears or put you to sleep.
Virtualization can be accomplished by using a variety of different technologies, depending on your needs. So lets explore and identify virtualization solutions. While Windows Server 2012 has several virtualization solutions to choose from, Hyper V is the most widely known though there are other options available. A Windows administrator needs to be aware of the solutions available to effectively choose the appropriate virtual solution for a variety of situations.
App-V: Client Configuration
Microsoft offers different versions of Hyper V, which is a hypervisor-based virtualization solution. There is a version that is integrated into Windows Server 2008 or 2012, or you can obtain a separate standalone product called Hyper-V Server 2012 containing the hypervisor, Windows Server driver model, virtualization capabilities, and supporting components such as failover clustering.
While Hyper-V is not new to Windows Server 2012, it does include a number of new features not present in Windows Server 2008. There is now support for up to 64 processors and 1 terabyte of memory for Hyper-V guests. Also new is the virtual hard disk format VHDX, which differs from the older VHD in it’s ability to use a larger disk capacity of up to 64 terabytes. The processor must be 64-bit in order for Hyper-V to be installed, to support hardware-assisted virtualization (Intel VT or AMD V), and the feature must be enabled in the system BIOS. Hyper-V can only be run on a physical host. You cannot run the Hyper-V service in another virtual machine (VM)—in other words you cannot run a VM inside another VM because the hypervisor must have direct access to physical hardware. Hyper-V can be installed as a role in Server Manager, among the benefits of Server virtualization:
- You can consolidate servers, reducing datacenter floor space and power consumption.
- It is invisible to users.
- Guest machines can use different operating systems.
- Hardware is used more efficiently.
- Server deployment is simplified.
- Offers virtual machine templates
Yet another benefit is a cloud-based platform for hosting virtual machines, production applications, and websites. Capacity can be increased and decreased automatically and quickly. This can mean your organization need not concern itself with infrastructure to host virtual machines, services, or applications. Since it is cloud based it is always available, providing unlimited storage and resources.
Hyper-V technology is also now available in a desktop OS version of Windows. This scaled down version of Hyper-V runs on Windows 8. Client Hyper-V requires a 64-bit system that has Second Level Address Translation (SLAT), which is a feature present in some 64-bit processors made by Intel and AMD. Requiring a 64-bit version of Windows 8 and a minimum of 4GB of ram. Hyper-V supports the creation of both 32-bit and 64-bit operating systems in the Virtual Machines.
To help enterprise organizations to upgrade to the latest version of Windows while still maintaining support for legacy applications. Microsoft Enterprise Desktop Virtualization (MED-V) enables management and deployment of Microsoft’s virtual PC Windows desktops. It is an extension of the compatibility modes that were introduced in Windows 7, which helped to resolve application incompatibility. MED-V allows applications to be run in Windows XP compatibility mode.
Microsoft also offers a desktop delivery system solution called Virtual desktop Infrastructure (VDI), where you deploy actual client operating systems to users with one very big difference in that the operating systems don’t have to be the same. Each user can have a separate dedicated VM, or you can create a pool of VMs that users can share although only one user will share a VM at any one time. In either instance, the Virtual Machines run on the server. The desktop is presented to end users via Remote Desktop Protocol (RDP), the main benefit of Virtual Desktop Infrastructure being that it allows the user seamless access to the same desktop from any device.
Virtual Desktop Infrastructure streamlines Administration making it easier to deploy new desktop operating systems and with all the required software applications. End users can have access to multiple desktops, so that they can work in the desktop environment that they need at that time. Virtual desktops are created from VM templates and can be persistent or pooled. User profiles can also be tied to specific virtual desktops, so that regardless of the logon location the user has a specific desktop experience.
Microsoft Virtual Desktop Infrastructure (VDI)
Terminal Services Application Mode server has been renamed as Presentation Virtualization. Multiple users connect to the same server and share the server OS environment as each user runs their own instance of the same application. This centralizes the delivery of applications, while reducing cost and increases security. The users perspective is that the operating system they are using is the central servers operating system, while the application is able to run multiple instances on the same operating system. There are a variety of presentation virtualization technologies available:
- Remote Desktop Services
- Full Desktop with RDC
- Application using RemoteApp
- Remote Access through Remote Desktop Gateway Terminal Services
While application virtualization is very much like desktop virtualization, rather than virtualizing the entire desktop or operating system, only a single application is virtualized. End users are not aware that some or all of the applications are not locally installed even though it is possible they can be cached for offline use. Virtualization of applications provides the following benefits:
- Application isolation
- Application portability
The ability to run different versions of the same application on one computer
To Be Continued in Part 2...