VMware vSphere HA Cluster - Datastore Heartbeating Condition

Datastore Heartbeating Condition

Question

In a vSphere High Availability (vSphere HA) cluster, which condition can be detected by datastore heartbeating? (Choose the best answer.)

Answers

Explanations

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A. B. C. D.

B.

https://docs.vmware.com/en/VMware-vSphere/6.5/vsphere-esxi-vcenter-server-65-availability-guide.pdf

In a vSphere High Availability (HA) cluster, datastore heartbeating is used to detect the state of the datastore connectivity. Each ESXi host in the vSphere HA cluster sends a heartbeat signal to the shared datastore at regular intervals. If a host fails to receive a heartbeat signal from the datastore for a specified number of seconds, it is considered to have lost access to the datastore.

The condition that can be detected by datastore heartbeating is a Datastore All Paths Down (APD) event, which is option D. This event occurs when all paths to a shared datastore are lost, and it can be caused by various issues, such as network connectivity issues, storage controller failures, or storage array issues.

When a Datastore APD event occurs, the affected host detects the loss of connectivity to the datastore and triggers a vSphere HA failover. This causes the virtual machines running on the affected host to be restarted on other hosts in the vSphere HA cluster that have access to the datastore.

In contrast, option A, fault tolerance VM failover, is not detected by datastore heartbeating. Fault tolerance (FT) is a feature that provides continuous availability for virtual machines by creating a secondary copy of a virtual machine that runs on a different host. If the primary virtual machine fails, the secondary virtual machine takes over without any disruption. FT uses a different mechanism to detect failures, such as network heartbeating and a secondary FT logging network.

Option B, network isolation, is also not detected by datastore heartbeating. Network isolation occurs when a host loses network connectivity to the rest of the vSphere HA cluster, which can happen due to network misconfigurations or failures. This can cause a host to falsely detect a failure and trigger a failover, but it is not related to datastore connectivity.

Option C, virtual machine disk failure, is also not directly detected by datastore heartbeating. Virtual machine disk failures can cause data corruption or loss, but they are not related to the connectivity of the datastore. However, virtual machine disk failures can trigger a vSphere HA failover if they cause a virtual machine to become unresponsive or crash.