Explanation/Reference:
Reclaim nearly 100% of unused space.
HP's thin reclamation technology continually hunts down wasted space in fine-grained, 16k increments and returns that capacity to the system for use by other applications.
Note:
Thin provisioning, in a shared-storage environment, provides a method for optimizing utilization of available storage. It relies on on-demand allocation of blocks of data versus the traditional method of allocating all the blocks up front. This methodology eliminates almost all whitespace which helps avoid the poor utilization rates, often as low as 10%.
Over-allocation or over-subscription is a mechanism that allows a server to view more storage capacity than has been physically reserved on the storage array itself. This allows flexibility in growth of storage volumes, without having to predict accurately how much a volume will grow. Instead, block growth becomes sequential. Physical storage capacity on the array is only dedicated when data is actually written by the application, not when the storage volume is initially allocated.
References: http://www8.hp.com/us/en/products/data-storage/data-storage-technology.html?
compURI=1225575#.VzxC5Wh96Uk