For a large environment, a heat map is helpful. The three heat maps are Time Remaining, Capacity Remaining, and VM Remaining. If your cluster sizes are not standardized, create another heat map, and use the number of ESXi hosts to show the size difference.

The

Clusters Capacity

widget provides a table with details. The number of ESXi hosts are color coded as smaller clusters have a relatively higher overhead. Select a cluster from the table to view the capacity details that are automatically displayed.

Ensure that the performance of the cluster meets your SLAs.

You can view the trend of the three which are CPU, disk, and memory components together on the

Overcommit Ratio

chart. In general, your CPU overcommit should be the highest, followed by the disk (because of thin provision). Memory overcommit tends to be near one due to its nature as cache.

Use the line chart in the

Allocation

widget, to see the trend. The data is averaged hourly.

In the

VM Count

widget, the trend line of the number of VMs over time is important to spot if there are many newly provisioned VM. If you see that the VMs are increasing but demand remains low, it indicates a sign of potential demand in the future.

Reservation can impact the efficiency of your cluster. Your cluster could be low on capacity because of real workload or just reservation. If your cluster size varies, complement the reservation number by showing a relative value. Once you have a standardized number, you can visualize them on a heat map.

Good cluster capacity does not indicate that there is no issue at the ESXi level. Unbalance is a common problem, especially in large clusters and stretched clusters.

The

ESXi Hosts in a Cluster

table displays all the member ESXi hosts. You can see the unbalance clearly, thanks to the color code. The color code reflects the unbalance.

The

99th percentile Performance

column takes the 99th percentile value of the ESXi Performance (%) metric.

Select an ESXI host to view the details. Both the

CPU Workload (%)

and the

Memory Workload (%)

trend line charts display if there is a steady demand, cyclical demand, rising demand, or declining demand. The trend is as important as the present value. View trends over a longer time. Utilization is displayed for three months and not one week. The daily average is displayed and not the hourly average. The focus is on memory consumed and not memory active. Memory consumed includes the total memory consumed, so it includes the memory consumed by VMkernel. Both total and usable utilization in terms of memory and CPU are displayed and provides the absolute amount of capacity.