What action can minimize downtime for VMs during host maintenance in a vSphere environment?

Using vMotion to migrate VMs to another host is the most effective way to minimize downtime during host maintenance in a vSphere environment. vMotion allows for live migration of running virtual machines from one host to another without server downtime. This means that the VMs continue to operate seamlessly while their physical resources are being moved, ensuring that services remain available to users.

In scenarios where host maintenance is necessary, such as applying patches or upgrades that require reboots or system changes, vMotion enables administrators to maintain high availability for applications and workloads. By dynamically shifting VMs to a different host, the system can ensure that users experience minimal disruption.

Other options, such as manually powering off VMs and restarting them post-maintenance, would lead to significant downtime as each VM would be unavailable during the process. Cloning VMs to a backup host does not provide a live solution and could be time-consuming and resource-intensive, while configuring VM settings for auto-start only ensures that VMs will start automatically after host maintenance is completed, which does not assist in avoiding downtime during that maintenance window. Thus, vMotion is the preferred choice to maintain service continuity.