The full rack version of the SPARC SuperCluster T4-4 contains six Exadata Storage Servers. The half rack version of the SPARC SuperCluster T4-4 contains three Exadata Storage Servers. Redundancy in the Exadata Storage Servers is achieved two ways:
Through connections between the Exadata Storage Servers. For more information, see Exadata Storage Server Physical Connections.
Through components within the Exadata Storage Servers:
Power supplies – Each Exadata Storage Server contains two power supplies. The Exadata Storage Server can continue to operate normally if one of the power supplies fail, or if one of the power distribution units fail.
Disk drives – Each Exadata Storage Server contains 12 disk drives, where you can choose between disk drives designed for either high capacity or high performance when you first order the SPARC SuperCluster T4-4. The SPARC SuperCluster T4-4 software provides redundancy between the 12 disk drives within each Exadata Storage Server. For more information, see Cluster Software for the Database Domain.