Arrrrggghhh - the nightmares are starting again LOL !!!
When the system I was on switched from R21 MVT to SVS, there were endless meetings about moving from the drum TSO swap devices to TSO page devices using said drums (and someone wanted PLPA there too). The question was (I think) how to reformat the volumes over a weekend and make the change and hope you didn't need to go back the other way. ISTR about two months of spotty TSO response until a couple of PTFs and changes to channel layout fixed most of the problems (until MVS - a story for another time).
