The load on a Fully Automated HA/DRS cluster is critically unbalanced.
What condition could cause this issue?
A. DRS is disabled on one or more virtual machines.
B. The migration threshold is set to Moderate.
C. Storage vMotion is not enabled on the cluster.
D. Storage DRS is disabled on the datastore hosting the cluster’s virtual machines.
Correct Answer: A
Explanation/Reference:
Explanation:
VMware DRS (Distributed Resource Scheduler) is a load balancing utility that assigns and moves computing workloads to available hardware resources in a virtualized environment.
DRS is enabled at the host cluster level. However, it can be disabled on virtual machines (VMs) to prevent the VMs being migrated to other hosts.
In this question, we have a VM or multiple VMs on a host that have DRS disabled. The cluster is unbalanced because the VMs with DRS disabled are using more resources than the DRS enabled VMs on the other hosts.
Incorrect Answers:
B: DRS makes its recommendations by applying stars to indicate how much the recommendation would improve the cluster’s performance. One star indicates a slight improvement, and four stars indicates significant improvement. Five stars, the maximum, indicates a mandatory move because of a host entering maintenance mode or affinity rule violations. If DRS is set to work in Fully Automated mode, you have the option to set a migration threshold based on how much it would improve the cluster’s performance. The lowest threshold, which is the most conservative, only applies five-star recommendations; the highest threshold, which is very aggressive, applies all recommendations. In this question, the migration threshold is set to moderate. A setting of moderate, would not cause a cluster imbalance because the VMs would be moved before that happens. Therefore, this answer is incorrect.
C: Storage vMotion is used to migrate VMs between storage datastores. It is not required in a DRS cluster and is not used to balance the load between DRS hosts. Therefore, this answer is incorrect.
D: Storage DRS is used to balance the load between multiple datastores. Storage DRS is not used to balance the load between DRS hosts. Therefore, this answer is incorrect.
References:
https://pubs.vmware.com/vsphere-55/index.jsp?topic=%2Fcom.vmware.vsphere.troubleshooting.doc%2FGUID-0C132C85-E7BF-445E-925D-31420A06B01C.html