The following figure shows the hardware architecture of the Hitachi Virtual Storage Platform One Block 20 storage systems.
The VSP One Block 20 storage systems feature a duplexed configuration for each controller, front-end module, back-end module, power supply unit, backup module, battery, and CFM and a redundant configuration for the power supply units and cooling fans. These redundancy and backup features eliminate all active single points of failure, no matter how unlikely, to provide ultra-high reliability and data availability. In addition, the firmware upgrades and adding or replacing components can be performed nondisruptively while the storage system is in operation. Controller boards can be replaced nondisruptively as long as host clients have a path to both controllers. (During maintenance and replacement of a controller board, the front-end modules and the back-end modules attached to the controller board are blocked.)