Thanks LucD ,
The KB is mostly for vMotion issues.
The common vMotion issue I face is
1. Change host and datastore vMotion is greyed out.
2. Change host vMotion is greyed out.
3.vMotion hungs at certain percentage like 14% , 21%.
likewise.....
in such issue we were not aware how many host has such vMotion issues, until those host goes down due to hardware or other reason and we come to know the VM's didn't moved to other host.
I was looking something...which should just test vMotion funcationality from one host to other host in the cluster across entire vCenter. its fine even if we take first VM from each host to get migrated to other host in each vCenter to test vMotion functionality.