System data sets

The system data sets are IMS system libraries. These data sets are user data sets (not known to SMP/E).

IMS file system path names

IMS uses the following paths that reside in a z/OS® file system:
  • SDFSJCIC: Maps to PathPrefix/usr/lpp/ims/ims15.3/imsjava/cics/IBM/
  • SDFSJHFS: Maps to PathPrefix/usr/lpp/ims/ims15.3/imsjava/IBM/
  • SDFSJSAM: Maps to PathPrefix/usr/lpp/ims/ims15.3/imsjava/samples/IBM/
  • SDFSJRAR: Maps to PathPrefix/usr/lpp/ims/ims15.3/imsjava/IBM/
  • SDFSIC4J: Maps to PathPrefix/usr/lpp/ims/ims15.3/ico/IBM/

IMS SYSDEF data sets

The following data sets are initially loaded by Stage 2 of the IMS system definition (SYSDEF) process.
  • IMS.FORMAT
  • IMS.OBJDSET
  • IMS.PROCLIB
  • IMS.REFERAL
  • IMS.TFORMAT

JOBS data sets

JOBS data sets include various IMS jobs.

MODBLKS data sets

The IMS control region and the MSVERIFY utility use IMS.MODBLKS data sets that contain the IMS system definition output for the control block modules that are affected by online change. The MODBLKS data sets include:
  • IMS.MODBLKS
  • IMS.MODBLKSA
  • IMS.MODBLKSB

RDDS data sets

Resource definition data sets (RDDS) contain resource definitions and resource descriptor definitions for the MODBLKS data sets. The RDDS data sets include:
  • IMS.RDDSnn

A minimum of 2 RDDSs are required to support the export function.

TCFSLIB data sets

TCFSLIB data sets contain TCO SCRIPTS.

IMS.JOBS data set

JOBS contains job streams that are submitted for execution by either the IMS operator command: /START REGION or the z/OS command START IMSRDR,MBR=. You must customize any jobs that are stored in this data set with your installation job names, job statement parameters, and other pertinent specifications. This data set also contains the RACF® password or user ID (on a job statement), and therefore must be read protected. You can assign a RACF password and user ID to this data set, and optionally code a RACF System Task Authorization exit routine to verify the use of protected data sets. Otherwise, system security cannot be assured.

This data set has the following attributes:
DSORG
Partitioned
DSNTYPE
PDS
RECFM
FB
LRECL
80
BLKSIZE
Multiple of 80.

IMS.MODBLKSA, IMS.MODBLKSB data sets

The MODBLKSA and MODBLKSB data sets contain MODBLKS members. When one of these libraries is active (in use by the online system), the contents of IMS.MODBLKS are copied to the other, or inactive, library for use during the next online change process.

IMS.MODBLKSA or IMS.MODBLKSB can be brought online by a sequence of master terminal operator /MODIFY commands.

Before running online, you should APF-authorize these data sets to the z/OS system.

The MODBLKS data sets can be defined as either partitioned data sets (PDSs) or partitioned data sets extended (PDSEs). If a MODBLKS data set is defined as a PDS, the size of a member of the data set is limited to 16 M. Alternatively, if a MODBLKS data set is defined as a PDSE, the size of a member of the data set is up to 2G in size. Whether a MODBLKS data set is defined as a PDS or a PDSE depends on the required number and size of the following resources for your environment:
  • Database, as defined by DDIRLEN in macro DFSDDIR
  • Program, as defined by PDIRLEN in macro DFSPDIR
  • Routing code length, as defined by RCTELEN in macro DBFRCTE
  • Transaction, as defined by SMBTOTSZ in macro IAPS
To define your MODBLKS data sets as PDSEs, specify DSNTYPE=LIBRARY on your allocation job.
These data sets have the following attributes:
DSORG
Partitioned
DSNTYPE
PDS or PDSE
RECFM
U
LRECL
0
BLKSIZE
Greater than or equal to 32760. Default 32760. IMS.SDFSRESL, MODBLKS, MODBLKSA, and MODBLKSB should have the same BLKSIZE.

IMS.OBJDSET data set

The OBJDSET data set contains the assembler output that is created during IMS system definition Stage 2 execution. You specify the name of this data set in the IMSGEN macro.

This data set has the following attributes:
DSORG
Partitioned
DSNTYPE
PDS
RECFM
FB
LRECL
80
BLKSIZE
Multiple of 80 less than or equal to 3200. This BLKSIZE limit of 3200 is a binder-imposed maximum for data sets containing object modules that are referenced by INCLUDE.

IMS PROCLIB data set

The IMS PROCLIB data set contains the cataloged procedure and control statement members. Some control statement members are created by IMS system definition. Other control statement members and procedures are generated by SMP processing and users might copy them from the IMS.SDFSPROC data set. It also contains user-created control statement members that are used to tailor IMS. After system definition, you might need to move some procedures to SYS1.PROCLIB.

This data set has the following attributes:
DSORG
Partitioned
DSNTYPE
PDS or PDSE
RECFM
FB
LRECL
80
BLKSIZE
Multiple of 80.

IMS.TCFSLIB data set

The TCFSLIB data set contains control statement members (scripts) used by IMS time-controlled operations (TCO).

This data set has the following attributes:
DSORG
Partitioned
DSNTYPE
PDS
RECFM
F
LRECL
80
BLKSIZE
80