There is no change to the RLP in R28 or R29.  The steps you describe are what we recommend to remove LUNs from the Reserve LUN Pool.  If you can stand the downtime, there is one possible work-around.  Example for one mirror:  Shut down your host than fracture the mirror(s) - it should be consistent at this point as the host shutting down should flush all writes out of the host.  Destroy the mirror which will release the reserve LUN(s), remove the LUNs from the Reserve LUN Pool, add the new LUN, create the mirror and add the original secondary image but do not check "Initial Sync Required". Then bring up the host - if you use the same secondary image for each mirror, the data should still be consistent as it was when the host was shut down. This has worked - but it is not an approved EMC proceedure.  glen
At present, the only way I know to do just about anything with a RL that's already been "assigned" to a mirror is to destroy the mirror, thereby releasing the LUN back into the RLP where it can be removed from the RLP, migrated to a different RG, deleted and replaced with a LUN of a different size, etc.  This is pretty disruptive, considering the mirror must then be re-created and a full sync of the source LUN performed, and the new mirror will unpredictably grab some RLP LUN that's not already allocated at that time.  Is there an easier or less disruptive way to:   For that matter, is there any way to instruct a mirror to stop using "its" reserved LUN and use a different, specific, reserved LUN in its place?
Looking for a less disruptive way to release Reserved LUNs.