Thin Provisioning has two main features:

1. Allows you to allocate the volume size more flexibly. In a normal allocation method, or thick provisioning, you can allocate volume size that is bigger than the actual need, but cannot be recycled to the storage pool. Using thin provision can allocate the needed space or upon requirement.
2. Allows you to claim a size larger than the physical size. When used together with the first feature, you can just expand the storage pool such as joining more logical drives (RAID) when needing more volumes.

It is possible that a Thin-Provisioning volume may not get new space it needs because of running out of space caused by other fast growing volumes. Try to prevent this, Infortrend also implements a feature that you could specify minimum reserved space for specific Thin-Provision volumes.

See sample screenshot below for creating a volume.

If you take a look at the volume name Post-Production, the drive space displays 100TB, but the physical space is only 373.46GB. You can specify the pre-provisioned space to 100GB.