In computing, thin provisioning involves using virtualization technology to give the appearance of having more physical resources than are actually available.
The term thin provisioning is applied to disk layer in this article, but could refer to an allocation scheme for any resource.
For example, real memory in a computer is typically thin-provisioned to running tasks with some form of address translation technology doing the virtualization.
This methodology eliminates almost all whitespace which helps avoid the poor utilization rates, often as low as 10%, that occur in the traditional storage allocation method where large pools of storage capacity are allocated to individual servers but remain unused (not written to).
With thin provisioning, storage capacity utilization efficiency can be automatically driven up towards 100% with very little administrative overhead.
[1] Previous systems generally required large amounts of storage to be physically pre-allocated because of the complexity and impact of growing volume (LUN) space.