Each SPARC SuperCluster T4-4 contains one Sun ZFS Storage 7320 appliance, in either the full rack or half rack version. The Sun ZFS Storage 7320 appliance consists of the following:
Two Sun ZFS Storage 7320 storage controllers
One Sun Disk Shelf
Redundancy in the Sun ZFS Storage 7320 appliance is achieved two ways:
Through connections from the two Sun ZFS Storage 7320 storage controllers to the Sun Disk Shelf. For more information, see Sun ZFS Storage 7320 Appliance Physical Connections.
Through components within the Sun ZFS Storage 7320 appliance itself:
Power supplies – Each Sun ZFS Storage 7320 storage controller and Sun Disk Shelf contains two power supplies. Each Sun ZFS Storage 7320 storage controller and the Sun Disk Shelf can continue to operate normally if one of those power supplies fails.
Disk drives – Each Sun ZFS Storage 7320 storage controller contains two mirrored boot drives, so the controller can still boot up and operate normally if one boot drive fails. The Sun Disk Shelf contains 20 hard disk drives that are used for storage in the SPARC SuperCluster T4-4, and 4 solid-state drives that are used as write-optimized cache devices, also known as logzillas. The SPARC SuperCluster T4-4 software provides redundancy between the disk drives. For more information, see Understanding the SPARC SuperCluster T4-4 Configurations.