Building Your Virtualized Network

Server Virtualization
Server virtualization is a tangible, physical infrastructure in a local environment where multiple servers are able to operate on the same one machine, or hardware. As a result, this now one, single host server controls access to all resources and multiple servers located on it. Many businesses who invest in virtualization to store, access, and secure the majority of their data also embrace the use of cloud computing to maximize the IT services it provides. Unlike virtualization, cloud computing is an intangible product ~ a service; it remotely controls and interacts with all the applications and data stored on your server. As a System's Administrator or other IT personnel at your company, you are the expert your staff, colleagues, and stakeholders defer to when problems arise. Here’s some things to consider when considering implementing server virtualization at your company:

Advantages of virtualization:

• conserves physical space by consolidating hundreds (or thousands) of servers into one server running multiple virtual environments
• provides a way to run the same application on multiple servers (redundancy) without having to purchase additional hardware
• creates isolated, independent systems for you to test new applications or operating systems without worrying about affecting other applications or having to buy a dedicated physical machine to run tests
• permits the movement (migration) of a virtual server from one physical machine in a network to another
• centralized storage that prevents theft, damage, or loss of critical data
• reduces expenses by eliminating the need to: buy additional individual dedicated servers to get more computing power, pay staff overtime or hire additional staff to maintain multiple servers. Further cost savings are experienced by: a reduced utility/energy bill, an increase in available physical square footage workspace, and a tax break for creating less of a carbon footprint
• if at all, only one application on one operating system can be affected by an attack vs. the whole system

Disadvantages of virtualization:

• divides up the processing power among all the virtual servers and makes those servers dedicated to applications with high demands on processing power run slower
• the system could crash if the server can't meet processing demands
• the more virtual machines a physical server must support, the less processing power each server can receive
• too many virtual servers could impact the server's ability to store data
• can only migrate a virtual server from one physical machine to another (and only if both physical machines use the same manufacturer's processor)
• if migration isn't an option, then all the applications running on the virtual servers hosted on the physical machine will be unavailable during maintenance 

Though the disadvantages seem drastic, rare is the case that any of that will happen or be impossible to manage or recover. By utilizing VM software and appliances, you will still be able to maintain your networks integrity better than you would with standalone servers as everything is consolidated to one host machine.