The Model A20, an active/active dual-node base unit, is designed to provide fast data access, simultaneous multiprotocol support, expandability, upgradeability, and low maintenance requirements.The Model A20 supports a maximum of 40 drives. The Model A20 consists of two PCMs that are designed to provide failover and failback function, helping improve overall availability. The Model A20 is a 2U rack-mountable storage controller.