In our shop, we use EMCSNAP. Mainly our folks use it for copying VSAM files, but I am working on snapping some sequential files. What I am finding is that after the snap completes, unused space is not released. For example:
//PS0150 EXEC PGM=EMCSNAP
//*******************************************************************
//ZEBBNR DD DUMMY
//SYSPRINT DD SYSOUT=*
//SYSTERM DD SYSOUT=*
//DD01 DD DSN=SCTD.TSTE.PSW.STMT.SCSTMTS.IM,
// DISP=SHR
//*D01O DD DSN=&OSCPD..PSB.STMT.SCSTMTS.IM.&TM&GDG1,
//DD01O DD DSN=SCTD.TSTE.PSB.TEST.GDG(+1),
// DISP=(,CATLG),
// SPACE=(CYL,(1000,250),RLSE),
// DCB=(RECFM=FB,BLKSIZE=0,LRECL=800,DSORG=PS)
//QCOUTPUT DD SYSOUT=*
//QCINPUT DD *
GLOBAL MAXRC(4) -
HCPYMODE(SHR) -
REUSE(N) -
REPL(Y) -
MIG(PUR(Y)REC(Y)) -
COPYSMS(DATACLAS STORCLAS)
SNAP DS(INDD(DD01) -
OUTDD(DD01O))
//*******************************************************************
//ZEBBNR DD DUMMY
//SYSPRINT DD SYSOUT=*
//SYSTERM DD SYSOUT=*
//DD01 DD DSN=SCTD.TSTE.PSW.STMT.SCSTMTS.IM,
// DISP=SHR
//*D01O DD DSN=&OSCPD..PSB.STMT.SCSTMTS.IM.&TM&GDG1,
//DD01O DD DSN=SCTD.TSTE.PSB.TEST.GDG(+1),
// DISP=(,CATLG),
// SPACE=(CYL,(1000,250),RLSE),
// DCB=(RECFM=FB,BLKSIZE=0,LRECL=800,DSORG=PS)
//QCOUTPUT DD SYSOUT=*
//QCINPUT DD *
GLOBAL MAXRC(4) -
HCPYMODE(SHR) -
REUSE(N) -
REPL(Y) -
MIG(PUR(Y)REC(Y)) -
COPYSMS(DATACLAS STORCLAS)
SNAP DS(INDD(DD01) -
OUTDD(DD01O))
Some days, this file is at least 1000 cylinders, if not more. Somedays it is smaller. I have tried various SNAP commands and review the documentation in detail and have not found anything that would make this space release although the RLSE is coded on the SPACE parameter.
Any thoughts?