What does vSphere HA do in terms of providing availability for virtual machines?

vSphere High Availability (HA) is a feature designed explicitly to increase the availability of virtual machines (VMs). In the event of a physical host failure, vSphere HA automatically restarts the affected VMs on other hosts within the same cluster. This process minimizes downtime and helps ensure business continuity.

The mechanism works by continuously monitoring the health of the hosts in the cluster. When a host fails, vSphere HA detects this failure and automatically attempts to restart the VMs that were running on the failed host on the remaining hosts that are operational. This built-in fault tolerance capability is vital in maintaining service availability without manual intervention.

In contrast, the other options do not accurately describe the core functionality of vSphere HA. For instance, enabling low latency between VMs pertains more to network configurations or resource allocation rather than availability. Monitoring VMs for performance thresholds is generally managed by other tools and features within the vSphere ecosystem, such as vRealize Operations. Lastly, while creating backups is essential for data protection, it is not the role of vSphere HA, which focuses specifically on virtual machine availability rather than backup management.