This article describes the vCenter HA Cluster Health Alarm Rules.
vCenter Server
Details of each rule are as follows:
vCenter HA cluster state is currently isolated
⇒Some nodes in the vCenter HA cluster cannot communicate with each other.
vCenter HA cluster state is currently degraded
⇒Any node in the vCenter HA cluster has stopped or an error has occurred.
vCenter HA cluster is destroyed
⇒vCenter HA itself has been deleted.
japanese KB:vCenter HA クラスタ健全性アラームにおけるルールの詳細について