Creating the DWWMSGA, DWWMSGB, DWWDMSG, and DWWDUMP data sets

When the CICS® VR server address space is activated CICS VR dynamically creates, catalogs, and allocates both the CICS VR message data sets, the CICS VR trace, and dump data sets if the following requirements are met.

Naming conventions:

The data sets don't already exist
SMS-managed storage is available

Therefore, if SMS-managed-storage is available, you are not required to manually create these data sets before activating the CICS VR server address space. However, you might still need to refer to the naming convention specified to determine the names of the CICS VR-created data sets when you want to view their contents.

You can manually create and catalog the CICS VR data sets prior to activating the CICS VR server address space. However, ensure the manually created data sets follow the correct naming convention as described in Understanding the DWWMSGA, DWWMSGB, DWWDMSG, and DWWDUMP data sets naming convention. During activation of the CICS VR server address space, CICS VR first allocates any manually created data sets to the appropriate ddnames and uses them during address space processing, instead of dynamically creating them.

If you create the CICS VR data sets manually, ensure that you allocated sufficient contiguous primary storage for these data sets. Otherwise CICS VR server can not start.

This figure shows an example of JCL that can be used to manually create the DWWMSGA, DWWMSGB, DWWDMSG, and DWWDUMP data sets.

Figure 1. Example JCL to manually create the DWWMSGA, DWWMSGB, DWWDMSG, and DWWDUMP data sets.

        //*******************************************************
        //* PREALLOCATE DWWMSG DATA SETS
        //*******************************************************
        //* Each DWWMSG data set SPACE value should be
        //* 30 tracks or more
        //*******************************************************
        //DEFMSG EXEC PGM=IEFBR14
        //DWWMSG1 DD DSN=hlq.slq.DWWMSGA.systemname,DISP=(NEW,CATLG),
        //           SPACE=(CYL,(6),,CONTIG),
        //           DCB=(RECFM=FBA,LRECL=133,BLKSIZE=1330)
        //DWWMSG2 DD DSN=hlq.slq.DWWMSGB.systemname,DISP=(NEW,CATLG),
        //           SPACE=(CYL,(6),,CONTIG),
        //           DCB=(RECFM=FBA,LRECL=133,BLKSIZE=1330)
        //*
        //*******************************************************
        //* PREALLOCATE THE DWWDUMP AND DWWDMSG DATA SET
        //*******************************************************
        //DEFDUMP EXEC PGM=IEFBR14
        //*******************************************************
        //* The DWWDUMP data set SPACE value should be 30 tracks
        //* or more.
        //*******************************************************
        //DWWDUMP DD DSN=hlq.slq.DWWDUMP.systemname,DISP=(NEW,CATLG),
        //           SPACE=(CYL,(3),,CONTIG),
        //           DCB=(RECFM=VBA,LRECL=84,BLKSIZE=3120)
        //*******************************************************
        //* The DWWDMSG data set SPACE value should be 20 tracks
        //* or more.
        //*******************************************************
        //DWWDMSG DD DSN=hlq.slq.DWWDMSG.systemname,DISP=(NEW,CATLG),
        //           SPACE=(CYL,(2),,CONTIG),
        //           DCB=(RECFM=VBA,LRECL=84,BLKSIZE=3120)
        //*

Attention: The data sets created and allocated to the DWWMSG, DWWDMSG, and DWWDUMP ddnames for the CICS VR server address space must be separate from the ones used by the CICS VR panel interface and jobs that start CICS VR utilities. IBM® recommends that you:

Create and allocate separate data sets to the DWWMSG, DWWDMSG, and DWWDUMP ddnames used by the CICS VR panel interface, the allocations can be made in the CLIST used to display the CICS VR panel interface. Also, there is no specified naming convention for the data sets allocated to the panel interface.
Specify SYSOUT=* for the DWWMSG, DWWDMSG, and DWWDUMP data set allocations specified in batch jobs that run CICS VR utilities.

Sharing the message, trace, and dump data sets between the CICS VR server address space, CICS VR panel interface, and batch jobs could cause data to be overwritten.