Configuring VM Host Affinity in a Nutanix AHV-powered cluster ensures that VMs are placed on specific hosts to optimize performance or HA. However, after a host failure, if database VMs cluster on a single remaining host, it indicates that the affinity rules alone are insufficient to maintain high availability (HA) during failover scenarios. To prevent this, the administrator should configure anti-affinity rules, which dynamically ensure that VMs (e.g., database server VMs) are spread across multiple hosts. Anti-affinity rules override default VM placement behavior during failover, reducing the risk of a single point of failure by keeping VMs separated even after a host outage.

Option A (Assign additional backup VMs on the same host) is incorrect because placing backups on the same host increases risk rather than mitigating it.

Option B (Increase affinity zones) is incorrect as "affinity zones" is not a standard Nutanix term in this context, and it does not address dynamic VM separation.

Option C (Configure automatic host failover in Prism Central) is incorrect because while failover is managed by AHV, it does not inherently prevent VMs from clustering without specific rules.

Option D is correct as anti-affinity rules proactively distribute VMs, enhancing HA in failure scenarios.

This approach leverages Nutanix AHV’s VM placement policies to ensure resilience.

References

Nutanix Database Service (NDB) User Guide, Chapter 3: Configuring an NDB Environment, Section: Configuring VM Affinity and Anti-Affinity

Nutanix AHV Administration Guide, Section: VM High Availability and Placement Rules

Nutanix Certified Professional - Database Automation (NCP-DB) v7.5Blueprint, Section 3: Configure an NDB Environment