Shared Systems: Same Addresses for Tape Subsystems

When reading SMF data for systems A and B, the volume mount analyzer cannot make a distinction between Configurations One and Two.

                                |
 ┌────────┐        ┌────────┐   |    ┌────────┐   ┌────────┐
 │  SYSA  │        │  SYSB  │   |    │  SYSA  │   │  SYSB  │
 │        │        │        │   |    │        │   │        │
 └───┬────┘        └───┬────┘   |    └────┬───┘   └───┬────┘
     │                 │        |         │           │
     │ 0580-           │ 0580-  |         └───┐    ┌──┘
     │  059F           │  059F  |   0580-059F │    │ 0580-059F
  ┌──┴───┐          ┌──┴───┐    |            ┌┴────┴┐
  │      │          │      │    |            │      │
  │      │          │      │    |            │      │
  ├──────┤          ├──────┤    |            ├──────┤
  │      │          │      │    |            │      │
  ├──────┤          ├──────┤    |            ├──────┤
  │      │          │      │    |            │      │
  ├──────┤          ├──────┤    |            ├──────┤
  │      │          │      │    |            │      │
  └──────┘          └──────┘    |            └──────┘
      CONFIGURATION ONE         |      CONFIGURATION TWO
                                |
                                |
        CONFUSING

Configuration One: SYSA and SYSB do not share tape subsystems. However, each system has tape units with the same addresses, 0580-059F. In this case, the volume mount analyzer incorrectly assumes there is one tape subsystem.
Configuration Two: SYSA and SYSB share a tape subsystem. The volume mount analyzer correctly interprets that both systems use the same address range (0580-059F) to refer to one tape subsystem.

Therefore, merging SMF data for SYSA and SYSB in Configuration One might cause misleading or incorrect results for the Usage Report because the volume mount analyzer assumes that each unique address represents one and only one unit. See The Usage Report for more information.

Note: Do not merge SMF data from multiple systems if your installation has Configuration One. Analyze these SMF samples separately.