A customer has Metro Availability configured in Automatic Resume Mode between Site A and Site B What happens to VMs if Primary Site A has full network failure?

In a Metro Availability configuration using Automatic Resume Mode, a witness is configured to arbitrate failover decisions. When the primary site (Site A) experiences a full network failure, it loses connectivity to both the secondary site (Site B) and the witness. The witness detects the primary site's unavailability and automatically instructs the secondary site to take over. Site B then promotes its protection domain from standby to active, and the VMs registered in that protection domain are automatically restarted on Site B, ensuring business continuity with minimal downtime.

B. VMs continue to run on Site A following an automatic disable of protection domains.: With a full network failure, the storage on Site A becomes unavailable to the VMs, causing them to crash. The protection domain is disabled to prevent split-brain.
C. An administrator must unwitness in Site B and promote protection domains in Site B for VMs to restart: This describes a manual failover process. The purpose of "Automatic Resume Mode" with a witness is to avoid manual intervention.
D. An administrator must promote protection domains in Site B for VMs to restart.: This is also a manual failover step. Automatic Resume Mode automates this promotion based on the witness's decision.

1. Nutanix University, Nutanix Enterprise Cloud Administration (ECA) 6.5, Module 10: Data Protection, Lesson: Metro Availability. "With the automatic resume option, if the primary site fails, the witness VM triggers an automatic failover to the secondary site."

2. Nutanix Prism Element Web Console Guide v6.5, Section: "Protection Domain States for Metro Availability", Subsection: "Primary Site Failure Scenario (Witness)". "If the primary site fails, the witness allows the secondary site to take over automatically. The protection domain on the secondary site becomes active."

3. Nutanix Data Protection and Recovery with Prism Element v6.5, Section: "Metro Availability", Subsection: "Failure Scenarios". "In an automatic failure scenario, the witness arbitrates and allows the protection domain on the available site to become active."