DEVSUPxx specifies the installation default for device support options. DEVSUPxx is processed during the NIP phase of IPL. After IPL, customers can use system command SET DEVSUP=XX to activate the DEVSUP changes.
If no installation default is provided through the DEVSUPxx member, and storing data in a compacted format is not explicitly requested on a DD statement, dynamic allocation request, the MOD= parameter on the JES3 *CALL DJ command, or DCB macro, the system uses the compaction default for the device. For example, the compaction default for a 3480 is NOCOMP. To determine the compaction default for a particular device, see the planning or migration information that accompanies the device.
DEVSUPxx also specifies the installation default for the VOLID facility. The VOLID facility allows tape volumes written in 3480-2 XF (36-track) format and which are mounted on a tape drive not capable of reading this format, to be re-labeled by the OPEN or EOV label editor routines. The label editor routines permit the re-label option only when RACF® allows the user ALTER authority to the volume. The volume serial number passed to RACF is obtained from the VOLID mark written on the cartridge by the device, and placed in the sense data.
If no installation default for the VOLID facility VOLNSNS, is provided by using the DEVSUPxx member, the system assumes VOLNSNS=NO.
The MEDIAxx parameters of the DEVSUPxx parmlib member allow the customer to specify partitioning category codes. Library partitioning is the ability to partition volumes in an IBM® tape library between different z/OS® systems (or sysplexes). Partitioning allows each system (or sysplex) to limit its view of library volumes to only those volumes that it owns. This is accomplished when each system connected to a library uses unique category codes. The DEVSUPxx category codes are read during IPL and the codes are stored into the SSVT (replacing the default category codes).
The IBM Redbook IBM TotalStorage 3494 Tape Library:
A Practical Guide to Tape Drives and Tape Automation (SG24-4632)
lists all default Library Manager volume categories, the platforms
on which they are used and their definitions. This book is available
at the following URL: http://www.redbooks.ibm.com/abstracts/sg244632.html
DEVSUPxx also specifies the installation default for creating AL tapes. Use the ALVERSION keyword to specify whether AL tapes are created using the ISO/ANSI/FIPS Version 3 or ISO/ANSI Version 4 label standards. ALVERSION is also used to specify if the specified version level should override (force) the current Version 3 or Version 4 labels of an AL tape. ALVERSION is valid only if the AL tape data set is being opened for output processing to the first file of the first or only volume of the data set. Otherwise, the current AL version level of the tape will not be changed, even if force is specified. The default for ALVERSION is Version 3.
The TAPEAUTHxxx keywords in the DEVSUPxx parmlib member enable new options for tape data set security. For more details about the new support, see Enhanced security for tape data sets.
Use the DEVSERV QLIB,CATS command, which is documented in the z/OS MVS System Commands, to dynamically change the library partitioning category codes without IPL.
The EXPIRATION_MESSAGE keywords in the DEVSUPxx parmlib member allow you to handle expiration date processing for the opening of any non-VSAM data set on DASD.
The following keywords are set to their default values
prior to processing the current DEVSUPxx parmlib member:- KEYWORD:
- DEFAULT
- COMPACT
- NO
- ALVERSION
- 3
- NON_VSAM_XTIOT
- NO
- JES3_ALLOC_ASSIST
- NO
- TAPE_MULTI_VOLUME_ANOMALY
- NOT ALLOW NOT FAIL
- COPYSCB
- INPUT
- EXPIRATION_MESSAGE
- ALWAYS
For these keywords, in order for non default values
to take affect, they must be specified in either all DEVSUPxx parmlib
members processed at IPL or in the last or only DEVSUPxx parmlib member
processed either during IPL or after IPL using the system command:
SET DEVSUP=xx.