Contemplating moving our OES11SP2 file service cluster to OES2015SP1. (We run our cluster in a vmware set of hosts, one OES11SP2 in cluster per VMWARE host)

Which way would be better?

1. Add a few new OES2015SP1 servers to the cluster and migrate the volumes over to them?


2. Inplace upgrade the existing OES11SP2 servers to OES2015SP1?


3. Some other suggestion?

Thanks in advance

Dave G.