Once management of VMs and requests are under control, the focus can shift to capacity planning. IT planners need to know where to expect growth. Will it be storage? Or is it compute this year?
Virtualization capacity planning, however, is much more than simply tracking growth. The first -- and often-overlooked step -- is validating what you have. This should be done before taking that next step in planning for the future.
In many organizations, both physical and virtual servers fall under some type of enduring naming convention that probably hasn't been refreshed to keep up with today's growing virtual environment. This can generate confusion over a VM's name, ownership and function.
Fortunately, you have options. The use of the description field will help; if you’re using VMware, you also have the ability to tag a VM. The description and attributes can be placed on a VM during or after its creation to help generate a searchable list -- depending on which tags are selected. For example, you can tag certain VMs as "Citrix" or "Accounting" to signify a group or application.
Another key piece of information to add is the month and year of the VM’s creation. This allows the virtual administrator to run reports on which VMs are in use by a specific department or application. It helps determine usage for possible chargeback, and it can even uncover abandoned or excessive VMs from an old project or deployment.
Identifying and tagging machines from the start is somewhat easy. In an established environment, tagging existing VMs is not a quick or simple task. It is essential, though, in figuring out what you have.
Knowing which VMs belong to which groups allows an administrator to find out if those VMs are needed and if the resource allocation is appropriate.
Admins should look at the different ownership groups to identify trends in the requests. This will help establish a baseline for when and how many resources a particular group requests. You might find, for instance, that accounting added four new production servers in each of the past three years. Establishing trends of who is using what and how many permanent VMs are being added, along with what amount of temporary growth you need, helps an organization predict its needs.
Being able to look at VM performance in groups will also help to establish baselines for performance and capacity. Groups that are low resource users can be scaled back to a pre-determined VM resource level that is a more appropriate fit. VMs that are constrained on resources can be expanded as well, and VMs that show no activity can be investigated to see if they are still needed.
Seeing what you had before and what you have today will help you prepare for what you’ll need tomorrow. While no tool or technique can fully predict the future, you can get a pretty clear idea by accurately knowing what you have had.
Remember that virtualization management and capacity planning isn't about finding the best tool that can provide insight into an environment. It's about understanding what you have in your environment. There is not a quick or easy shortcut to that finish line, but the effort pays off.