Benefits of Virtualization
Source: www.energystar.gov
Before virtualization technology existed, server admins typically installed at least one physical server for each of their applications. The traditional one workload, one box approach meant that most servers ran at a low "utilization rate" – a fraction of total computing resources engaged in useful work. A 2012 New York Times article cited two sources that estimated the average server utilization rate to be 6 to 12%.
Server virtualization offers a way to consolidate servers by allowing you to run multiple different workloads on one physical host server. A "virtual server" is a software implementation that executes programs like a real server. Multiple virtual servers can work simultaneously on one physical host server. Therefore, instead of operating many servers at low utilization, virtualization combines the processing power onto fewer servers that operate at higher total utilization.
Virtualization improves scalability, reduces downtime, and enables faster deployments. In addition, it speeds up disaster recovery efforts because virtual servers can restart applications much more rapidly than physical servers. With virtualization, you can move entire systems from one physical server to another in just a few seconds to optimize workloads or to perform maintenance without causing downtime. Some virtualization solutions also have built-in resiliency features, such as high availability, load balancing and failover capabilities.
Savings and Costs
Virtualization enables you to use fewer servers, thus decreasing electricity consumption and reducing energy needed to cool the waste heat produced by the server.
Virtualization enables the repurposing and decommissioning of some existing servers. According to the Uptime Institute, decommissioning a single 1U rack server can annually save $500 in energy, $500 in operating system licenses, and $1,500 in hardware maintenance costs.
Deployment Considerations
Take inventory. It is easy to lose track of servers as time goes by, as mergers and acquisitions take place, as people procure servers without going through central IT, or as servers are retired or repurposed. The first step toward virtualization is identifying all servers in the organization. Take an inventory of computing resources and their associated application workloads.
Identify servers that should not be considered for virtualization. Servers that have privacy, security, or regulatory restrictions, or require ultra-high service levels, tend not to be the best candidates for virtualization or consolidation.
Group remaining servers by workloads. Group the server inventory into pools of workloads that can work off of the same physical server at the same time. "Development" workloads and "Production" workloads would most likely not work well together. As previously mentioned, some servers may not be able to share resources due to technical, security, privacy, or regulatory concerns. Answering the following questions allows you to pool workloads into groups and determine the computing resources required for each group:
- Who owns the server?
- What is the purpose of the server?
- What is the service level requirement?
- What is the location of the server?
- Is there a requirement for this workload to remain on a dedicated physical resource?
Examine memory. Virtual host servers tax memory more than CPU utilization. A recent Information Week survey of large data centers indicated that memory is more important than the CPU when evaluating servers in a virtualized environment.
Look into shared storage. In general, a virtual server system will require networked storage as physical host servers must be able to address the same storage at the same time.
Estimate processor resources required. Although not the resource that limits virtualization, processor requirements can be estimated by multiplying the reported utilization (% of processor utilized) by the total processor capacity (maximum processor frequency * number of processors * number of cores). This produces a GHz requirement that can be applied to target servers.
Track all virtual machines (VMs). Easy to deploy, VMs can get out of control if you are not careful. If new VMs are created for specific projects, be sure they are not forgotten once those projects are completed.
The increased flexibility, efficiency, and reduced cost that a virtualized server offers your IT infrastructure is well worth the effort. Contact us today to see if a virtualized solution is right for you.