The Capacity Overview dashboard provides an overview of the capacity of the data centers in the environment. You can navigate between the data centers and review the status of the objects to see if you must rebalance the resource capacity among the data centers.
You can use the dashboard widgets in several ways.
Use the Select an Environment widget to select a data center. You can use the filter to narrow your list based on several parameters. After you identify the data center you want to view, select it. The dashboard is populated with the relevant data.
Use the Total Capacity widget to view the total physical capacity of the environment that includes capacity assigned as High Availability (HA). The actual capacity is less than the total capacity displayed when you consider HA and a buffer.
Use the Reclaimable Capacity widget to understand the amount of resources that can be freed up by deleting the powered off VMs. You can reclaim capacity from idle VMs, active VMs, orphaned VMs, and non-VMs. However, this widget highlights the capacity you can claim from powered off VMs. Powered off machines are VMs that are in a powered off state for a minimum percentage in the observation period. The default minimum percentage is 90% in the last 30 days. You can change this setting in the policy.
Use the Memory Capacity Utilization Trend widget to view the overall memory capacity trend. This widget displays the total physical resources you have. The physical resources include a HA buffer and a utilization buffer. This widget also displays the total memory you have allocated to VMs. If the number is close to the total physical capacity, the VMs may contend for memory. Ensure that the contention level is lower than what you promise to your customers. The chart also includes the actual utilization of memory capacity. The actual utilization is based on the active memory and hence it tends to be lower, as VMs do not normally access most of their RAM at any given moment.
Use the CPU Capacity Utilization Trend widget to view the overall CPU capacity trend. This widget displays the total physical resources you have. The physical resources include a HA buffer and a utilization buffer, which reflects the total capacity. This widget also displays the total CPU capacity you have allocated to VMs. If the number is close to the total physical capacity, the VMs may contend for CPU. Ensure that the contention level is lower than what you promise to your customers. The chart also includes the actual utilization of CPU. The actual utilization is based on the CPU demand counter, which takes into account the CPU used to perform I/O on behalf of the VM. The ESXi host performs storage I/O and network I/O on behalf of the VM, and this may be performed on a core that is different from the one on which the VM runs. As a result, CPU demand is a more accurate reflection of the VM CPU usage.
Use the Disk Space Capacity Utilization Trend widget to view the amount of disk space allocated to a VM and the amount that is actually used. This information is helpful when you plan for thin provisioning.
Use the Capacity Utilization Distribution - What is Over or Under Utilized widget to view if the objects in the data center are overused or underused. You can then carry out suitable actions on objects that are over used.