The install message file contains PDS members that include message skeletons for the language. (For the English PDS and Japanese PDS that IBM® provides, each PDS member contains message skeletons for each MVS™ component.) The MVS message compiler converts the install message file into a run-time message file. The run-time message file for each language must be a VSAM linear data set.

To create the data set for the run-time message files, you need to specify the DEFINE CLUSTER function of access method services (IDCAMS) with the LINEAR parameter. When you code the SHAREOPTIONS parameter for DEFINE CLUSTER, use SHAREOPTIONS (1,3). For a complete explanation of SHAREOPTIONS, see z/OS DFSMS Using Data Sets.

Figure 1 shows a sample job that invokes Access Method Services (IDCAMS) to create the linear data set named SYS1.ENURMF.DATA on the volume called MMSPK1. When IDCAMS creates the data set, it creates it as an empty data set. Note that there is no RECORDS parameter; linear data sets do not have records.

//DEFCLUS    JOB 'ALLOCATE LINEAR',MSGLEVEL=(2,0),
//         CLASS=R,MSGCLASS=D,USER=IBMUSER
//*
//*        ALLOCATE A VSAM LINEAR DATASET
//*
///*DCLUST   EXEC PGM=IDCAMS,REGION=4096K
//SYSPRINT DD SYSOUT=*
//MMSPK1   DD UNIT=3380,VOL=SER=MMSPK1,DISP=OLD
//SYSIN    DD *
    DELETE (SYS1.ENURMF) CL PURGE
    DEFINE CLUSTER (NAME(SYS1.ENURMF) -
                    VOLUMES(MMSPK1) -
                    CYL(1 1) -
                    SHAREOPTIONS(1 3) -
                    LINEAR) -
           DATA     (NAME(SYS1.ENURMF.DATA))
 

When you have allocated a VSAM linear data set for each run-time message file, you can run the message compiler to convert the install message file for messages in that language. (You must allocate one VSAM linear data set for each run-time message file.)