Explanation: SUMMARY is an optional parameter
specifying a count of data sets, tracks, and bytes of the selected
data sets.
Defaults: None.
Note: - When you specify this parameter, DFSMShsm does not list information
about each data set. This parameter applies only to information from
the MCDS.
- The SUMMARY information is issued when you specify the LEVEL parameter
or the DATASETNAME parameter (with no data set name specified) and
the MCDS information is requested and available. The SUMMARY parameter
applies only to the DATASETNAME parameter (with no data set name specified)
and the LEVEL parameter.