The Reclaimable Capacity badge is a graphical representation of the amount of unused compute resources currently assigned to your virtual machines.

In vSphere, Reclaimable Capacity is only applied to virtual machines, as it is seen that VMs are fairly straightforward to right-size as requirements change in the environment. The same could not be said for hosts, for example, as adding or removing resources from physical hosts based on demand would not be seen as a common task.

Although Reclaimable Capacity only applies to virtual machines, objects such as Clusters, Hosts, Datastores, and other containers still have a badge (and associated score) due to the relationship of children VMs.

Reclaimable capacity has four specific items that impact the score. These are:

• Oversized virtual machines
• Idle virtual machines
• Powered-off virtual machines
• Unused file capacity

The Reclaimable Capacity score is based on the resource that has the highest percentage of Reclaimable Capacity divided by its total capacity. This score ranges from 0 (good) to 100 (bad), and for virtual machines this score filters up to the objects, parent containers.

The following screenshot shows an example breakdown of the Reclaimable Capacity badge with a score of 37. You can see that the CPU has the highest reclaimable capacity of 36.63%, which determines the badge score:

The Reclaimable Capacity Breakdown panel shows you how much of each resource can be reclaimed, also shown as a percentage of the provisioned resource.

In this example, CPU is the resource type that has the highest percentage of reclaimable capacity (about 36%).

Reclaimable Capacity might be in contrast to Health and Stress. An ideal environment without wasted resources creates stress, so it is important to balance the proper size of the virtual machine based on Stress and Reclaimable Capacity recommendations. Normally, the same virtual machine shows up as stressed from a memory perspective, but it is oversized from a CPU perspective.

The Reclaimable Capacity badge color indicates the following states:

• Green (<= 50%): No resources are wasted on the selected object
• Yellow (> 50%): Some resources can be used better
• Orange (> 75%): Many resources are underused
• Red (= 100%): Most of the resources on the selected object are wasted

vRealize Operations 6.6 offers an out-of-the-box dashboard called Capacity Reclaimable. From the Capacity Reclaimable dashboard, you can select a vCenter, Datacenter, or Cluster object to review for a top-down approach to gain resource efficiency:

A thumbnail view shows the total capacity that can be reclaimed in CPU, memory, and disk space. Disk space is the easiest to reclaim, since it is due to old snapshots and powered off virtual machines.

For CPU and memory reclamation, the dashboard offers some best practices. Removing CPU and memory often involves approvals and maintenance windows, so it is best to focus on larger VMs first where there is more benefit for the efforts. 

In either case, all of the lists provide a set of totals that serve as an estimate of resource gains for reclamation efforts. 

We will be covering dashboards in more detail later in this book.