As you have already seen, working with the reservations, shares, and limits on multiple levels might be a tricky job, and unfortunately, there is no mechanism directly built into vSphere to help you with the calculations.
You can either use Excel or any other tool to calculate the resources and model what-if scenarios based on the resource consumption. You can use DRS Entitlement Viewer, a free tool available at VMware Labs (https://labs.vmware.com/flings/drs-entitlement-viewer).
DRS Entitlement Viewer is a small application that can integrate with the vSphere web client (HTML5 only), and it can do all the calculations for you:
I would strongly suggest installing this Fling to your vSphere environment, especially if you are working with multiple resource pools and you have configured RLS settings on multiple items.
The installation is simple—all you need to do is download the Fling itself and follow these instructions:
- Unzip the plugin package to the /usr/lib/vmware-vsphere-ui/plugin-packages/ folder.
- Add the advanced options to the cluster:
- CompressDrmdumpFiles– 0
- DrmdumpResActions– 1
- Restart the vsphere-ui service:
- service-control --stop vsphere-ui
- service-control --start vsphere-ui
Once installed, you can see the new DRS entitlements section under the Monitor tab for each cluster.