Consider these implementation tasks for using DFSMS software support for 3592 Model J tape drives.

• For non-specific mount requests in a stand-alone (non-SMS) tape environment, there are no automatic system controls for WORM cartridges. This can result in inadvertent and irreversible writes to WORM media. Using the tape management system pooling support to set up pools to select WORM versus R/W tape media and selecting economy length versus standard length cartridges help to guarantee that the correct media type is mounted.
  In addition, SMS data class policies can be used to control WORM mounts for stand-alone, non-specific mount requests. There are two ways to enforce the data class media policy:

  • Specify the DEVSUPxx keyword, ENFORCE_DC_MEDIA=ALLMEDIATY. ALLMEDIATY enforces all data class media policies for all stand-alone scratch mounts.
  • Specify the DEVSUPxx keyword, ENFORCE_DC_MEDIA=MEDIA5PLUS. MEDIA5PLUS ensures data class media policies for MEDIA5, MEDIA6, MEDIA7, and MEDIA8 are enforced for stand-alone scratch mounts.
• In the manual tape library (SMS) environment, WORM scratch mounts can be managed through the tape management system pooling support instead of data class. New DEVSUPxx keyword, MTL_NO_DC_WORM_OK, allows a WORM scratch volume to be used, even if it was not explicitly requested through data class.
• For the IBM TotalStorage Enterprise Tape Cartridge (MEDIA5), use the performance scaling attribute specified through the ISMF data class application if you want to select optimal performance scaling for certain types of jobs and applications. The default setting is to use the tape to its full 300 GB capacity. This can be specified for tape allocations that are inside or outside an IBM tape library environment. The performance scaling option is not available on MEDIA6, MEDIA7, or MEDIA8 tape cartridge media.
  Note: In addition, the 3592 drive also supports a 260 GB segmented format of the 300 GB (MEDIA5) tape cartridge that provides fast access in the first 60 GB segment and slower access in the remaining 200 GB segment. However, this format is not currently supported in the zSeries environment and when detected during OPEN processing (file sequence 1, DISP=NEW), results in the MEDIA5 tape cartridge being reformatted to either its 60 GB scaled or 300 GB full capacity format as indicated in the performance scaling data class attribute.
• If you have mixed 3590-1 devices in a non-SMS environment, you need to define a unique esoteric name for each recording technology. Identify the esoteric names to DFSMShsm using the SETSYS USERUNITTABLE(esoteric1:esoteric1, esoteric2:esoteric2...) command to ensure that the correct device type is requested when the tape is mounted for input or output. If your installation uses SMS-managed tape devices or has a single 3590-1 recording technology, you do not need to define an esoteric for those devices; you might need to specify that DFSMShsm allows mixed devices in the 3590-1 generic name (see APAR OW57282).
• In the stand-alone (non-SMS) environment, perform these implementation steps:
  1. Define data classes or alter existing data classes to:
     • Use the performance scaling attribute with the IBM TotalStorage Enterprise Tape Cartridge (MEDIA5).
     • To take advantage of the new data class media enforcement support enabled through DEVSUPxx (ENFORCE_DC_MEDIA=ALLMEDIATY or ENFORCE_DC_MEDIA=MEDIA5PLUS).
  2. Update the ACS routine to assign the appropriate data class construct.
• In an IBM tape library environment, perform these implementation steps:
  1. Define or alter existing data classes to specify the recording technology, media type, and performance scaling attributes, as appropriate. The performance scaling attribute applies to the IBM TotalStorage Enterprise Tape Cartridge (MEDIA5). This option is not available on MEDIA6, MEDIA7, or MEDIA8 tape cartridge media.
  2. Define or alter existing tape storage group constructs.
  3. Update ACS routines to direct allocation to appropriate 3592 devices and media.
  4. Validate and activate the new or modified SMS configuration.
  5. Update parmlib member DEVSUPxx (as appropriate) with the MEDIAx parameters (MEDIA5, MEDIA6, MEDIA7, and MEDIA8) specifying the library partitioning category codes.

Related reading:

See Migration to the software support for 3592 Model J tape drives for migration information and implementation information.