When you check the compliance of a cluster against an image, vSphere Lifecycle Manager compares the software on each host in the cluster with the software specified in the image. If the image contains a firmware and drivers add-on, the compliance check also calculates the firmware compliance of the hosts with the image.

For example, vSphere Lifecycle Manager compares the ESXi version on each host to the ESXi version in the image for the cluster.

In addition to calculating the compliance state for each host, the compliance check gives you information about the impact that the remediate operation will have on a host, for example if remediation will cause host reboot or if maintenance mode is needed for the host.

Compliance information about the hosts in a cluster is displayed on the Updates tab for that cluster, in the Image Compliance card. The Image Compliance card displays a list of all hosts that are out of compliance with the image for the cluster. When you select a host, the compliance information about the host appears on the right.