A full system backup should be performed before all major actions such as a system upgrade. The backup is not required as part of the actual upgrade (as was needed for the R184.108.40.206 to R11.1 GA upgrade process. However is an absolutely necessary provision in order to recover should issues occur in the R11.1 SP2upgrade process.
1.Having fully verified the operation of all services at R220.127.116.11, backup the R18.104.22.168 servers. See Creating a Back Up.