Checking a MetroCluster does not require any special checks. Here are some considerations that may need to be taken into account.
Intentionally stopped vservers can be excluded. See Checking vServers on a Metrocluster
Interfaces from intentionally stopped vservers can also be excluded with an exclude pattern. See Instance Names
Volumes which do not have a state attribute are assumed to be hosted by a stopped vserver. These volumes are silently skipped by all volume checks.