Thin provisioning (TP) is a method of optimizing the efficiency with which the available space is utilized in storage area networks (SAN). TP operates by allocating disk storage space in a flexible manner among multiple users, based on the minimum space required by each user at any given time.
In the conventional storage provisioning model, also known as fat provisioning (FP), storage space is allocated beyond current needs, in anticipation of growing need and increased data complexity. As a result, the utilization rate is low. Large amounts of storage space are paid for but may never be used. In TP, these problems are eliminated while keeping overhead low. Added benefits include reduced consumption of electrical energy, smaller hardware space requirements and reduced heat generation compared with traditional networked storage systems.