Compressing a PDS library using JCL.

You can compress the PDS file using IEBCOPY Utility
//COMPRESS JOB (acct#),’COMPRESS A PDS Library’,CLASS=D,MSGCLASS=J
//* COMPRESS A PDS Library
//*
//STEP010 EXEC PGM=IEBCOPY
//INDD DD DSN=dsn.name,
// DISP=SHR
//SYSOUT DD SYSOUT=*
//SYSPRINT DD SYSOUT=*
//SYSIN DD *
COPY INDD=INDD,OUTDD=INDD
//SYSPRINT DD SYSOUT=*
//*
This will compress and remove unwanted storage.