Blog post

1.6.3 – Describe how Distributed Resource Scheduler (DRS) scores virtual machines

The VM DRS score is a metric that tracks a VMs execution efficiency on a given host. The cluster DRS score is a weighted average of the VM DRS scores of all powered on VMs in the cluster. 

The score is calculated every minute and if another host can provide a better score for the VM, DRS will recommend or move the VM. 

  • Values closer to 0% indicate severe resource contention 
  • Values closer to 100% indicate mild to no resource contention 

DRS computes these scores from an individual VM’s, CPU, RAM, and network metrics. 

In vSphere 7, the DRS algorithm runs every minute. The cluster’s monitor tab lists the VM DRS score and detailed metrics for all the VMs in the cluster. The VM DRS score page shows the following values:  

  • DRS score 
  • Active CPU 
  • Used CPU 
  • CPU Readiness 
  • Granted Memory 
  • Swapped Memory 
  • Ballooned Memory