Server Virtualization Unleashed

In order to know the term Server Virtualization, one needs to get through the concept of Virtualization. Virtualization is to create a virtual (not actual) description of anything (Computing related), which can be related to storage devices, operating systems, network resources as well as network platforms. Now coming to Server Virtualization, the concept becomes a bit easy to grasp. Running multiple operating systems on a single machine concludes server virtualization. On a different notation, dividing a physical computing server, into multiple virtual machines also leads to virtualization of the computer server.

With the help of certain software applications, the Computer server administrator can split a physical server into manifold isolated virtual environments. In some context, the virtual environments are also known as virtual private servers and can be tagged with the name of guests, instances and emulations.

In order to make a lame person understand the concept of Server virtualization, it can be pronounced as a multiple guest systems, running on one physical server, with an illusion, that, they are using their own hardware, which is not a reality. Virtualization software, a single computer host will be housing the guest computers, masking each other from one another and giving them a proprietary feeling, that, they are the sole users of the hardware.

Benefits of Server Virtualization

• Cost reducing- the main benefit of computer server virtualization is that it cuts down the cost. When multiple hosts use same hardware platform and sometimes the same applications to work in an environment, the cost of maintenance of the hardware is gets increased. But through virtualization concept, the cost of maintaining extra hardware is cut down and hence the savings can be pocketed.

• Migration or Portability of Guest machines- the guest machines created on a physical server oblige portability, where the virtual machines can be migrated from one machine to another, over a network, which is like the true concept of Migration. This migration is possible, even though, if the two physical machines are not running on same platform of hardware, operating system and processor. However, some limitations do apply to the last point, like the two physical server machines hardware and processors must come from same manufacture like both have to house Intel or an AMD processor(example).

• Administrative Overhead- with the clubbing of guest virtual machines, the overall administrative costs will be reducing and thus this can save organizational costs.

• Server Consolidation- when an approach to use the computer server resources to the fullest is successful, one can reduce the amount of servers an organization requires in real terms. It is indeed a perfect solution for Server Sprawl, where a situation arises, when more space is taken by the multiple servers, whose utilization is not up to the mark.

• Segregation- since the programmers can run the same software on virtual machines, without any interference to other virtual machines or the host, Segregation can be achieved.

• Disaster recovery due to redundancy- with the effective use server virtualization, the disaster recovery techniques can be improved and so the data continuity can be achieved. Since, most of the companies practice redundancy, which is running same application in multiple servers, in order to save it as a backup, data connectivity interruptions are brought down immensely.

More information related to Server Virtualization.

Server Virtualization Software’s

Server virtualization can be achieved by the utilization of the following Software’s:

• Microsoft Virtual PC and Virtual server

• VMware server, Workstation, Player and ESX Server

• XEN

• Virtual Iron

Server Virtualization Techniques

Server Virtualization is possible in three ways like Virtualization done at the:

1. Operating system level server virtualization- virtual guest operating system is modified in such a way, that it believes that, it is running on the same hardware, like the host operating system.

2. Full machine virtualization- in this virtual model, the virtual guest machine operating system is unmodified, but is controlled by a software emulating CPU called Hypervisor. Hypervisor works with the CPU of the physical server and its disk space. It serves as a platform for Virtual servers OS and masks the virtual machines from each other.

3. Para-virtual machine model- In this Para Virtual Machine model, the guest Operating system, or the virtual machine is modified with XEN software and its functions. In this technique of server virtualization, virtual machines know about each others presence and so are also capable of knowing the demands on the operating system, kept by other virtual systems. The entire system works like a cohesive or unified unit.

Limitations for Server Virtualization

• For all those server applications, which demand high processing power, SV or server virtualization is not apt.

• By creating multiple Virtual machines, on a physical server, the CPU gets to an overload saturation point and as a result, less processing power is observed.

• Migration of virtual machines is only possible on physical machines which work of identical platforms like same processors. Otherwise, the migration is not possible at all.

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