What are some things that rightsizing virtual environments can do for a business?
The practice of rightsizing virtual machines and components of your virtual system can have a good impact on these systems. That's why it's often a part of ongoing administration and management.
One thing that rightsizing can do is related to the organization of system resources. If a particular virtual machine is hogging resources because it was over-provisioned, rightsizing it can put those resources back in play. This is one of the most straightforward principles of using rightsizing in a corporate environment, for example, to take a VM that's allocated ten gigabytes but only using five, and decreasing the allocation to five gigabytes. However, administrators have to understand what the demands are at peak times to make sure that the rightsizing isn't excessive.
Rightsizing can also help, in some cases, with professional tug-of-wars over resources. For example, someone in an overall central management position may be looking at a distributed IT architecture and thinking that certain hosts or virtual machines could operate with a lower amount of resources. But the admin who owns that part of the system could argue that his or her domain still needs more resources. Rightsizing can help get these conversations resolved, and lead to investigations into exactly how many resources a particular part of the system needs.
In addition, rightsizing VMs can affect performance in a good way. Many administrators will testify that even the process of downsizing or cutting CPU can improve performance significantly. Part of this has to do with the way that CPU-ready metrics show individual system components competing with each other for processing turns. Changing the numbers of vCPUs or cores can change how the system experiences peak demand.
Although rightsizing can do a number of things for a business IT system, it only goes so far. The next step is dynamic provisioning through autonomic virtualization systems. These systems can go further and actually identify whether resources can be taken away and added later, or shared on a dynamic basis. This goes further than rightsizing, because it can allow for dynamic on-demand change without requiring human decision-makers to deliberate, communicate and actually manually change provisioning.