Server virtualization is the masking of server resources, including the number and identity of individual physical servers, processors, and operating systems, from server users. The server administrator uses a software application to divide one physical server into multiple isolated virtual environments. The virtual environments are sometimes called virtual private servers, but they are also known as guests, instances, containers or emulations.
Server virtualization on the x86 platform has been around now for more than a decade, yet many in the industry still consider it a “new” technology. But those of us who have already adopted the technology in our own environments have grown to believe we can’t live without it. Many of us also have the opinion that there is simply no going back to a “physical-only world.”
There are three popular approaches to server virtualization: the virtual machine model, the paravirtual machine model, and virtualization at the operating system (OS) layer.
There are many benefits to an IT organization or business when choosing to implement a server virtualization strategy. Let’s have a look:
By collapsing physical servers into virtual servers and reducing the number of physical servers, your company will reap a tremendous savings in power and cooling costs. Additionally, you’ll be able to reduce the datacenter footprint which can include diesel generator costs, UPS costs, network switch costs, rack space and floor space.
Reduce hardware vendor lock-in
While not always a bad thing, sometimes being tied down to one particular server vendor or even one particular server model can prove quite frustrating. But because server virtualization abstracts away the underlying hardware and replaces it with virtual hardware, data center managers and owners gain a lot more flexibility when it comes to the server equipment they can choose from. This can also be a handy negotiating tool with the hardware vendors when the time comes to renew or purchase more equipment.
Faster server provisioning and deployment
Server virtualization enables system provisioning and deployment within minutes, allowing you to clone an existing virtual machine without the hours and costs normally spent installing a new physical server. Companies with virtual environments already look back and cringe at the grueling process of filling out a purchase order, waiting for the server to arrive and then waiting hours for the operating system and applications to finish installing. Time and cost add up substantially, not to mention the growing number of racks and cables you would have to purchase to accommodate for the increasing number of physical servers. Datacenter virtualization is most certainly necessary for most businesses to keep up with the explosion of data resources needed to keep pace with competitors.
Reduce the data center footprint
This one goes hand in hand with the previous benefit. In addition to saving more of your company’s green with a smaller energy footprint, server consolidation with virtualization will also reduce the overall footprint of your entire data center. That means far fewer servers, less networking gear, a smaller number of racks needed – all of which translates into less data center floor space required. That can further save you money if you don’t happen to own your own data center and instead make use of a co-location facility.
Improved disaster recovery
Perhaps the greatest benefit of server virtualization is the capability to move a virtual machine from one server to another quickly and safely. Backing up critical data is done quickly and effectively because your company can effortlessly create a replication site. Most enterprise virtualization platforms contain software that helps automate the failover during a disaster. The software also allows you to test a disaster recovery failover-think of it as your data center’s own fire escape plan. If a data center disaster occurs, your infrastructure is already set up to take appropriate measures for a swift and safe recovery. Try achieving that with arrays of physical servers – now that’s a real disaster.
Virtualization saves significant energy costs
Among other server virtualization benefits, the migration of physical servers to virtual machines allows you to consolidate them onto fewer physical servers. The result? Cooling and power costs are significantly reduced, which means not only will you be “going green”, but you will also have more green to spend elsewhere. According to VMware, server consolidation reduces energy costs by up to 80%. Another major plus is the ability to power down servers without affecting applications or users.
Increase staff productivity
Having fewer physical servers means there are less of them to maintain and manage. Applications that used to take days or weeks to provision are now done in minutes. This leaves your IT staff more time to spend on more productive tasks such as driving new business initiatives, cutting expenses and raising revenue.
Reduced hardware costs
It is said that humans theoretically only use 10 percent of their brain command; most of the servers in a strictly physical environment are heavily underutilized, using an estimated 5-15 percent of their capacity. When you implement a virtualized server / cloud computing approach, hardware utilization is increased because one physical server can now hold multiple virtual machines. Applications no longer need their own server because each virtual machine on the physical server now runs them. In 2011, IDC reported a 40 percent reduction in hardware and software costs for IT departments that adopted a server virtualization strategy.
Features like vMotion, storage vMotion (svMotion), DRS, and VMware high availability (VMHA) all result in virtualized servers being up and running so much more than those same servers that were running directly on physical hardware.