Thin Provisioning on the DS8000 has evolved. With the availability of the DS8000 Release 8.1 Modification 1 code, Thin Provisioning is now available using small or large extents, for both Open Fixed Block (FB) volumes and or z/OS Count Key Data (CKD) volumes. We call such volumes, Extent Space Efficient (ESE) volumes.
Using small extents (1 GiB or 21 cylinders) Thin Provisioned ESE volumes offers an elegant and efficient alternative to the former FlashCopy Space Efficient implemetation which was based on the now discontinued Track space Efficient (TSE) implementation.
For an overall understanding of how thin provisioning now works on the DS8880 and to get insights into the functional design and its implementation, as well as usage with DS GUI or the DS CLI, refer to this newly published IBM RedPaper :