If ever you encounter DRS issues in any of your vCenter cluster environments may need to get a DRS dump file generated in order to troubleshoot the issue. The file itself is called drmdump and contains various calculations that DRS uses to measure possible benefits to migrate VM’s.
Locations for these files:
vCenter Server Appliance
Full Windows vCenter instance
What’s really cool is VMware also offers an online tool called VM Resource and Availability Service (URL: http://hasimulator.vmware.com), telling you which VMs can be restarted during the ESXi host failures. Simply upload your metric file in order to give you the results. Really helpful in simulating the failure scenarios that can occur.