S — short data set information

If you select option S, information about the selected data set is displayed. The information displayed by option S is the same as that displayed by option S of the Data Set utility (option 3.2), but it differs from option I in two respects. Information for partitioned data sets, when displayed by option S, lacks the number of maximum and used directory blocks, and the number of members. For sequential data sets, options I and S display the same information. You can not enter a volume serial when you are requesting information on multivolume data sets.

Note:

The space for data sets allocated in blocks is calculated as if all of the tracks, including the last one, contain only full blocks of data. Any partial "short" blocks are ignored.
The information shown for current space utilization is the actual data that the data set contains, based on the number of allocation units (blocks, tracks, bytes, megabytes, and so on) that have been written. For a data set allocated in units other than tracks and cylinders, it does not include the unused portion of a track that is only partially filled.
For example, if a data set allocated in bytes with block size of 600 has one block written to a device with a track size of 1000, 600 bytes of data are written and the remaining 400 bytes cannot be used by a different data set. A track is the smallest possible unit of physical allocation to a data set on DASD. ISPF reports 600 bytes used while other products (such as ISMF) report 1000 bytes used. ISPF reports the space occupied by data in the data set. ISMF reports the space used by this data set that is not available for use by another data set. The difference is a relative indication of the effectiveness of the block size used when the data set was created.

Figure 1 shows a short format example of data set information for a partitioned data set. This is the short format ISPF uses to display data set information when DFSMSdfp is not installed or not available, or when the Storage Management Subsystem is not active. See Short information for managed data sets to see how ISPF displays data set information when these products are installed, available, and active.

Figure 1. Short data set information (ISRUAIP)

                             Data Set Information
                                                                   More:     +
Data Set Name . . . . : MYPROJ.DEV.SOURCE

General Data                           Current Allocation
 Management class . . : STANDARD        Allocated cylinders : 1
 Storage class  . . . : BASE            Allocated extents . : 1
  Volume serial . . . : MVS8WF
  Device type . . . . : 3390
 Data class . . . . . : **None**       Current Utilization
  Organization  . . . : PO              Used cylinders  . . : 1
  Record format . . . : FB              Used extents  . . . : 1
  Record length . . . : 80
  Block size  . . . . : 27920
  1st extent cylinders: 1
  Secondary cylinders : 1
  Data set name type  : PDS

  Creation date . . . : 2002/07/08      Referenced date . . : 2002/07/31
  Expiration date . . : ***None***

Command ===>
 F1=Help      F2=Split     F3=Exit      F7=Backward  F8=Forward   F9=Swap
F12=Cancel

The "Allocated units" and "Used units" fields can vary, depending on the value that was specified in the "Space units" field when you allocated the data set. For example, Figure 1 shows what the short format of the Data Set Information panel would look like if the data set was allocated by specifying CYLS in the "Space units" field.