In RHV web portal, Select “Compute” -> “Cluster” -> Select one cluster object -> click “Edit” -> click “Migration Policy”, there is a control called “Resilience Policy”, this note explains how “Resilience Policy” controls VM live migration during an outage.
Basically “Resilience Policy” controls how virtual machines running on the host in “Non-operational” state in RHV web portal are live migrated to other hosts in the same cluster.
A host in outage may appear in “Non operational” state or “Non responsive” state the difference of which is,
Something is wrong with the configuration of the KVM host. The RHEVM engine can still communicate with the KVM host, though.
It can be a failure in the connectivity of KVM host to any of the cluster components, say one storage domain.
The RHEVM-engine cannot communicate with the KVM host via vdsm. In simple terms, there is a break in RHEVM-engine->KVM host communication path. It may be due to network split, dead vdsm, firewall, etc.