MDC question

[Steve Gentry]

Greetings.   I have defined 512meg of main storage to be used for mini disk caching.  0meg from XSTORE.   How can I tell how much of that 512meg is being used or is it assumed that it is all being used?  The  QUERY MDC gives the percentage of storage being used for MDC i.e, 512meg / 6 gig = 12%
I'm trying to determine if I'm over allocating or under allocating.
Thanks,
Steve