Anyone know of a way to force the use of the newer MVCs so the older ones don't get mounted?

 We have converted all of our RTD's from C's to D's. We issued re-claims on all tapes so we would know that all data is now in D format. We now have a lot of empty MVCS. Many of them have not been used in a few years or ever..

We only issue re-claims when the MVC's are 98% free. My real question is. How can we force the use of the newer MVCS so the older ones don't get mounted and reclaimed all of the time?

I would like to see most of the new empty MVC's be used before it starts using the older media.