The following example allocates 100 MB of primary space on each of five volumes:

   //DD1  DD  DSN=ENG.MULTIFILE,DISP=(,KEEP),STORCLAS=GS,
   //         SPACE=(1,(100,25)),AVGREC=M,UNIT=(3380,5)

1. After 100 MB is used on the first volume, 25 MB extents of secondary space is allocated on it until the extent limit is reached or the volume is full. The system assumes DISP=NEW because the user omitted the first DISP value.
2. If more space is needed, the 100 MB of preallocated primary space is used on the second volume. Then, more secondary space is allocated on that volume.
3. The same process is repeated on each volume.