The Virtualization is a product by Microsoft Technologies, which consists of a wide range of options and alternatives for the corporate clients,from which they can choose the right tool for their business. Its often a complex process to decide upon a Microsoft products as it has wide range of products available for high as well as medium sized businesses, which creates confusion in the selection.
Each technology and product have specific focuses, according to the scenario so, if you are developing a project for Microsoft virtualization it is important that you have clearly defined the concept of each tool and in which conditions it should be used. Another issue is that its not very particular that on what should be emphasized upon, is there any virtualization technology, that is higher than any other?
Why Use Virtualization?
Virtualization offers multiple benefits for the IT environment and it is not another wave of technological or fugitive thing. Nowadays many companies that still do not have virtualization deployed are probably considering its deployment in the medium term.
Things that controls the use of virtualization:
Consolidation Servers : Reducing the amount of servers helps to drastically reduce consumption power.
Reduction cost allocation of physical space : Companies that make co-location data centers seeking to reduce costs with physical space for servers.
Decrease electric power consumption for data center cooling : A large number of servers in a datacenter also requires a high cost to cool the environment where they are. There are two points analysis of electric power consumption : power consumed by server ( equipment) and power consumed by system cooling CPD / Datacenter to cool the servers.
Scenarios Disaster / Recovery : Easy migration of virtual machines between hosts makes it quite attractive option.
Reduction costs of maintenance contracts for servers : Critical servers require high maintenance contract, according to the existing SLA.
The reduction in the number of servers brings benefit of the direct maintenance costs.
Migration Application : The ability to migrate applications to new operating systems quickly and dynamics are the major facilitators to maintain an environment always updated and in homogeneous network.
Environments test / development and approval : Many homologation tests are flawed because not always the gaps production are identical environmental approval. With virtualization it’s possible to have a replica of the production servers as faithful as possible in approval, dramatically increasing the reliability of the tests.
Independence physical limits of the equipment : It is very common nowadays to find the following scenario: a server has an X application and suddenly comes the need to increase memory and / or processor, but the hardware does not support it. It is not so simple to “clone” a disk and download the image on another server with a total different hardware.
Through virtualization there’s the dependency on the hardware a manufacturer.
Once these are clear, then it is time to understand different types of Virualization Technology.
Virtualization Server Hardware
Through a Hypervisor or virtualizer layer, you can host multiple virtual machines. This technology requires support for instruction in the virtualization server processor (Intel -VT or AMD- V). Currently this technology is available in Hyper-V, a component of Windows Server 2008 and Windows Server 2008 R2. Also There is a special version called Windows Server Hyper-V Server, which basically consists of a Windows Server 2008 with graphical interface reduced just doing the virtualization role and completely free.
The components of the Hyper -V is available in the following distributions of Windows Server: Windows Server 2008 R2 Standard, Windows Server 2008 R2 Enterprise, Windows Server 2008 R2 Datacenter, Hyper-V Server 2008 R2.
Windows Server 2008 R2 Foundation does not have Hyper-V. In addition to that you can not virtualize a server running Windows Server 2008 R2 Foundation, because its license is OEM.
Virtualization Server Software
This type of virtualization is not used more intensively, since limits on multiple virtual machines points (out of memory, logic processors, etc). This technology represents the next Microsoft product that is Microsoft Virtual Server 2005 R2 SP1. The architecture of the product is like,that there is no benefit in new hardware because besides being the same old product does not support the new virtualization technologies and hardware that are available in Windows Server 2008 R2.
Virtualization software server is based on software that runs on a layer above the operating system. This means that the communication has not virtualizer directly with the hardware, making it impossible to have some performance gains and scalability.
Virtualization Session and Presentation
Formerly known by the name Terminal Services (TS), the technology has assumed new name in Windows Server 2008 R2, to be called as Remote Desktop Services (RDS).
In the virtualization Session, application is installed on the RDS server and made available to the client through a specific protocol (RDP – Remote Desktop Protocol). Only application screen or the whole desktop of the server is sent to the user’s machine. The traffic is generated for updating the screen, keyboard, mouse and sound when any. All application processing and memory usage are the same in RDS server. In case of failure of communication network between the server and RDS client, it is not possible to run the application until the link is restored.
An ideal scenario for this type Virtualization is the remote office. It is very common to find companies that have remote offices, and most of the complaint is just the access to applications that are in the array and need to be implemented in subsidiary. When installing a server in the array with the service RDS / TS it is possible just to install the application on this same server and permit access to branches via RDS / TS Client. The experience of access to the user’s remote location will be improved, as if it were accessing the application of the matrix.
For larger scenarios complexity and / or management is used for Citrix XenApp, a component that is run under the RDS (not possible to deploy the Citrix XenApp without RDS). Another very common in virtualization projects session is the use of thin clients, which make role of the workstation.
Through the Microsoft’s Application Virtualization (App-V) an application runs on the user’s desktop in an isolated environment independent of registry and other operating system files. Unlike the Remote Desktop Services, App-V uses memory and processing the user’s machine, but it is possible to run the application even without network connectivity with the server App-V.
App-V is available at Microsoft Desktop Optimization Pack (MDOP) and the same is acquired only by those customers holding Software Assurance agreement.
This technology is much similar to the model Virtualization of server hardware. Many developers and IT professionals need to have a virtual machine at your disposal, without complexity of having a Windows Server with Hyper-V. The tool allows create and manage virtual machines is Microsoft Virtual PC and it does not requires more than the hardware that has support for virtualization (Intel-VT or AMD-V).
Another component of the Virtual PC and that can be installed part is the XP mode, which consists of a virtual machine Windows XP. Through the Mode XP, an application installed on is published as a program item in the Start Menu physical machine, allowing only the application screen is performed and displayed to the user of the machine physically. It can be mainly used where there are applications that only work with Windows XP.
Virtual Desktop Infrastructure
Virtual Desktop Infrastructure (VDI) is a feature that allows you to centralize desktops of users in a virtualized server virtualization. It possibly work as follows:
a)Dedicated Virtual Machine – every user who accesses has its own virtual desktop (VM) with all the desktop customization details. Each virtual machine has its own user.
b)Virtual Desktops Pool – a pool of multiple virtual machines is shared with a group of users. There is a specific virtual machine to each user, and desktop customization are made using techniques such as Folder Redirection and Profile Roaming.
Another important point is process of sending desktop screen of virtual machine for the season user. This process is done together using the Remote Desktop Services (RDS) and Windows Server 2008 R2.
Virtualization Management on the Server
The product line System Center refer to product management at Microsoft. One of its components is System Center Virtual Machine Manager 2008 R2. The SCVMM allows you to manage Host virtualization and virtual machines and supports the following server virtualization systems:
- Windows Server 2008 w / Hyper-V
- Hyper-V Server 2008
- Windows Server 2008 R2 w / Hyper V
- Hyper-V Server 2008 R2
- Virtual Server 2005 R2 SP1
- VMWare ESX through VMware VirtualCenter
Important to note that managing a host with VMWare ESX is not done directly by SCVMM, because you must have VirtualCenter for that. This means that SCVMM is VirtualCenter Manager that manages this with VMWare ESX hosts.
If you have a System Center Operations Manager 2007 R2 in your network infrastructure, then you can enable the integrated use of two tools, using so-called PRO (Performance and Resource Optimization). This feature allows SCVMM move automatically (or manually) a virtual machine from one host to Another case is detected any choke-points in performance.
Virtualization Management on the Desktop
For those clients who wish to implement the use of Virtual PC on a larger environment and / or requiring greater control of virtual machines then it can be possible through the Microsoft Enterprise Desktop Virtualization (MED-V). With MED-V it is actually possible to distribute the Virtual PC images and manage from a central point.
Basically, the product is a part of the package of Microsoft Desktop Optimization Pack (MDOP).