The ProLiant Storage System RSO/U is a storage system that consists of a ProLiant Storage System Model U11 with the Recovery Server Option (RSO) I/O Board installed at the factory.This storage system includes all of the software and documentation required to support the Recovery Server Option: On-Line, Standby, and Online Server Controller Recovery Option (OSCRO). The ProLiant Storage System RSO/U supports all requirements for RSO (P/N 304117-B21 & 304117-291), for use with the ProLiant S/100 Cluster or UNIX Non-Stop Clusters.