Recommendation: Use multiple CFs with global connectivity. This ensures maximum availability, simplifies systems management and allows for nondisruptive lock transfer in the event of a CF outage.
You must have at least one CF connected to all systems capable of VSAM RLS within the Parallel Sysplex® (for lock structure duplexing, you must have at least two CFs). For multiple CFs, select one facility with global connectivity to contain the master lock structure. For maximum availability, use a second CF with global connectivity. In the event a CF becomes unavailable, the SMSVSAM address space can transfer its in-storage duplexed copy of the locks to the other available CF without causing any application disruption.
You can attach CFs which do not contain the master lock structure to a subset of the systems. A CF cache structure that is referenced by a storage class cache set must have at least the same connectivity as the storage groups to which the storage class maps.
Depending upon your existing configuration, you might also need additional CF processor, storage, and link capacities to utilize system-managed duplexing.