When virtualizing natively thin provisioned storage arrays, such as HP 3PAR, are there some best practices that need to be followed. The external volumes will be part of an HDT pool and host LUNs provisioned from the pool. Some questions/concerns are related to reusing blocks from the external storage. Should zero page reclaim be run regularly on the HDS array to "tell' the back-end storage which physical blocks from it's pool can be reused? If zero page reclaim is not run regularly, would this mean that the external storage array will potentially fill up with "stale" blocks? Any guidance here is appreciated.