Mouse-over for larger image.   ThinProvisioning provides the following functions Create and grow thin provisioning pool Create a disk pool (a/k/a "RAID Group") that can be used for thin LUNs. The thin provisioning disk pool is a Dynamic Pool, so it can grow by as little as one HDD at a time, and that capacity is immediately available: you don't have to wait for HDD formatting or RAID rebalancing. Create and grow thin LUNs Create thin LUNs that only consume capacity in slices when data is written to them. You can over-provision a thin provisioning pool using thin LUNs, such that if all of the LUNs were full, you would consume more physical capacity than you actually have. You can increase the size of thin LUNs without disruption. Notification of capacity thresholds Monitor the capacity of the thin provisioning pool and thin LUNs via email, SNMP, log files, or the GUI. When a pool or LUN reaches the threshold, the system will automatically notify you. There are two pool thresholds: the Early Capacity Threshold, which is optional, and the Actual Capacity Threshold. For each thin LUN, there is a single capacity threshold that will send out notifications when it is reached. LUN Quota For each LUN, there can be a quota, which is a hard limit for the capacity consumed by the LUN. Once the quota is reached, no more capacity can be consumed by the LUN. That prevents the LUN from unexpectedly taking up capacity when other LUNs need it.