I believe this is the link to the "bug".
http://h20000.www2.hp.com/bizsupport/Te ... ical_006_1The way I read that, if you have plenty of free space, you should be OK. How much is plenty is the question. Even with VV based tunesys, you can watch the system consume new space as it moves the data from one CPG to another... then when done you can force a compaction on the old CPG, or if its empty, just delete it.
How many VV's do you have? It might be better to use tunecpg to move all your luns from the old CPGs to new ones to get the rebalance done. I posted a script I used to assist me in getting this done.
viewtopic.php?f=17&t=215 If space is tight on the orginal node pairs and spindles, you may want to do a couple tunecpgs, followed by a compact CPG to free up the allocated space left behind to make room for more tunecpgs.