VMware Certified Professional - Data Center Virtualization (VCP-DCV) Practice Exam

What are two likely causes for a DRS cluster to become unbalanced?

1. Migration threshold is too low.

2. Affinity rules are preventing virtual machines from being moved.

3. A device is mounted to a virtual machine preventing vMotion.

4. Migration cost is too low.

The correct answer is: Affinity rules are preventing virtual machines from being moved.

The selection of affinity rules as a cause for a DRS (Distributed Resource Scheduler) cluster to become unbalanced is accurate because these rules dictate which virtual machines must remain on the same host or be kept separate from one another. When affinity rules are applied, they can constrain the DRS's ability to effectively balance workloads across the cluster. If these rules are overly restrictive, DRS may not be able to migrate virtual machines between hosts, leading to potentially uneven resource distribution. For a deeper understanding, examining the context of other options can shed light on why they don’t point to the same issue. For example, a low migration threshold would indicate that DRS will react sooner to imbalances, which generally aids in balancing the cluster rather than hindering it. Additionally, if a device is mounted to a virtual machine and prevents vMotion, while it can create a temporary unbalance, it is not inherently linked to systemic imbalances across the cluster, as it relates to individual VM configurations. Lastly, a low migration cost might encourage more migrations rather than resulting in a state of unbalance, as DRS would be more inclined to move VMs around if the costs are low. These factors emphasize how affinity rules can significantly restrict DRS functionality, leading