The EMC Clariion CX4 is a very flexible box. One of the ways which it enables admins to get the most bang for their buck is by utilising Virtual (Thin) provisioning. This effectivelly enables an admin to create a pool of storage from which smaller volumes of storage (thin LUNs) are provisioned. See below:
Many people will see thin provisioning as the answer to all their problems in terms of storage management.. No. It still needs to be monitored, managed and some intelligent thinking still needs to go into what volumes will be thin provisioned. The EMC Clariion CX4 also has some limitations around thin provisioning.
Also please bear in mind, that although a disk pool for thin provisioning may contain more drives than RAID allows, the maximum size of a single LUN may not exceed 14TB.