Unified storage is a shared storage device that provides consolidated block and file services to open system clients and physical and virtual servers. Applications and users access data over a shared network.
Large numbers and various types and release levels of direct-attached storage or internal storage can be difficult to manage and protect as well as costly due to very low total utilization rates. Unified storage provides the cost savings and simplicity of consolidating storage over an existing network, the efficiency of tiered storage, and the flexibility required by virtual server environments

Dell EqualLogic FS7610

Memory : 24GB DDR3 1066MT/s per controller
Connectivity: 1GbE configuration options , 10GbE configuration options
File system capacity: Up to 509TB

Dell Compellent FS8600

Processor : Dual Intel E5620 4 core
Memory : 48GB DDR3 1066 MHz per controller
Connectivity: 8Gb FC configuration ,10Gb iSCSI 
configuration options
File system capacity : Up to 3.2PB