>I didn't see your dsmfmt command.

That's because you don't use dsmfmt on logical volumes - just files.
Logical volumes are used as raw blocks by ADSM.

In any case, from the evidence it's not apparent why the Est Cap value
turns out to be 200 MB.  lslv command output may shed light on the matter
(and maybe not).
       Richard Sims, Boston University OIT