you can run it anyway ..can't hurt anything, worth case it will not reclaim a thing. Most likely you will need to do something else to get the most out of it.
here is my scenario:  we have a thinly provisioned 2tb lun on my hp box & host is using only 1tb out of 2tb lun now we migrated this data to vmax using open replicator{Hot pull} by creating a same 2tb thin lun in vmax.  now my question since host actually used only 1tb lun now on vmax frame after migrating how can we re-cliam  the 1tb un-used space out of a 2tb thin lun.  is this something like making zero's is possible & shrink the 2tb lun to actuall used space....?    appreciate for every one's response....
question regarding open replicator