You need to allocate the file with IDCAMS first.  Here is the JCL I use --

// <jobcard>

//*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
//*
//* DEFINE AND FORMAT ADDITIONAL DATABASE SPACE
//*
//*- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
//ALLOC    EXEC PGM=IDCAMS
//SYSPRINT DD  SYSOUT=*
//SYSIN    DD  *
 /* ALLOCATE DB SPACE ON A 3390 VOLUME  */

    DEF CL(NAME(ADSM.PROD.BFB20) LINEAR -
           KILOBYTES(2403360) VOL(DSMB00))
    LISTC ENT(ADSM.PROD.BFB20) ALL
/*
//*
//FMTBFB20 EXEC PGM=DSMFMT,PARM='/ADSM.PROD.BFB20'
//DSMAMENG  DD  DSN=SYS1.CMD.MSG(ANRMENU),DISP=SHR
//SYSPRINT  DD  SYSOUT=*
//SYSTERM   DD  SYSOUT=*
//*
//*
//

Bill Colwell
The Charles Stark Draper Laboratory
Cambridge Ma.


_________________________Reply Header_________________________
Author: ADSM-L AT vm.marist DOT edu
Subject: DSMFMT COMMAND ON MVS
10-29-1997 04:59 PM

Does anyone know the syntax for the DSMFMT command on MVS?  I am trying
to create a file using this command but I am not sure how to path the
file out to the DASD.

Thanks
Tony Kenney
Seagate Software, Inc.
Tkenney AT smg.seagatesoftware DOT com