please see my comments in line starting with ""
if i add a new resource in a dg with vcs running,then is not necessary to freeze the group that dg belong.
<<< correct
Ex-i add a new volume in DG then no freeze that group.
If i replace a disk from a volume in dg with vcs run-then i must freeze that group?
<<< freeze the service group is highly recommended. however, if the related VM resources are offline, replacing disks in dg is not considered VCS related, its just a VM operation
if i change ip of nic in dg i must freeze group?
<<< if they are controlled by VCS, you need to offline the service group then do it.
