I wrote a COBOL program years ago that uses HPVOLINFO to go through and
report each volume set, and each member of the volume set.  The output
looks like this;

SYS.PUB% run volinfo2.util.smga
Begin run of VOLINFO2 at 14:46:07

There are          1 Volume Sets on this system
There are          9 disks on Volume Set
%MPEXL_SYSTEM_VOLUME_SET%

LDEV Drive Type     Volume Member Name          Total Capacity    Space
Used
----------------------------------------------------------------------------
  16 ST15150W       MEMBER16                        16,776,624
7,736,160
  15 ST15150W       MEMBER8                         16,776,624
11,297,424
  14 ST15150W       MEMBER7                         16,776,624
11,481,856
  13 HPC2490AM      MEMBER6                          5,294,144
3,757,472
   5 HPC2490WD      MEMBER5                          8,330,528
5,883,584
   4 HPC2490WD      MEMBER4                          8,330,528
5,555,904
   3 HPC2490WD      MEMBER3                          8,330,528
5,493,728
   2 HPC2490WD      MEMBER2                          8,330,528
5,429,392
   1 HPC2490WD      MEMBER1                          8,330,528
2,299,168


Let me know if you want a copy of the source or object.

shawn