A replication ring is a set of identical processes running on all nodes in the cluster.
The basis of clustering is the replicated database (RDB). An instance of the RDB is maintained on each node in a cluster. There are a number of processes that use the RDB to ensure consistent data across the cluster. These processes include the management application (mgmt), volume location database (vldb), virtual-interface manager (vifmgr), and SAN management daemon (bcomd).
For instance, the vldb replication ring for a given cluster consists of all instances of vldb running in the cluster.
RDB replication requires healthy cluster links among all nodes in the cluster. If the cluster network fails in whole or in part, file services can become unavailable. The cluster ring show displays the status of replication rings and can assist with troubleshooting efforts.