Component No. 2: Validating
While modeling "what if" scenarios is an important first step to continually ensuring optimal performance, it is equally important to validate that changes will not have a negative impact on infrastructure performance.
Validation spans between the modeling stage and the monitoring stage of the PAL, because it is equally critical to initially validate performance-impacting changes in preproduction, as well as to continually monitor and validate performance over time. If you cannot validate that a certain change will impact infrastructure performance in either a negative or positive way, there is significant risk to making that change.
Component No. 3: Monitoring
The ongoing monitoring of shared resource utilization and capacity is absolutely essential to knowing how the virtual environment will perform. When monitoring resource utilization, IT staff will know whether resources are being over or underutilized. Not allocating enough resources (based on usage patterns and trends derived from 24/7 monitoring) will cause performance bottlenecks, leading to costly downtime and SLA violations. Over-allocating resources can drive up the cost per virtual machine, making a ROI much harder to achieve.
By continually monitoring shared resource utilization and capacity in virtual server environments, IT can significantly reduce the time and cost of identifying current capacity bottlenecks that are causing performance problems, tracking the top resource consumers in your environment, alerting you when capacity utilization trends exceed thresholds, and optimizing performance to meet established SLAs.