SPOOL offload facility Spool is the primary medium for all JES2 data. All input jobs and system output (SYSOUT) are stored on the spool. JES2 gives your installation the capability to offload (transmit) data from the spool to a data set and later reload (receive) from the data set to the spool. The spool offload facility can use either tape or DASD as the offload medium. Spool offload eases the migration from release to release by lessening the impact of a cold start.
OFFLOAD SPOOL就是定期把某些特定种类的JOB的OUTPUT也就是SYSOUT保存到TAPE或DASD上，作为一种ARCHIVE的手段，比如一周执行一次把MSGCLASS=9的JOB OUTPUT全部写到TAPE上，然后删除在SPOOL上的记录，以维持SPOOL DS的合理使用，当然OFFLOAD到TAPE上，也有对应的还原手段，即LOAD回SPOOL，这里就不做介绍了。
1. Display and decide which OFFLOAD dataset to use
首先看看当前系统定义了那些OFFLOAD DS，这个一般是在JES2PARM里面定义的默认值
$D OFFLOAD
$HASP882 OFFLOAD1 DSN=OSD.MIB.OFFLOAD3,STATUS=DRAINED,
$HASP882 ARCHIVE=ONE,CRTIME=RESET,LABEL=SL,PROTECT=NO,
$HASP882 RETPD=30,TRACE=NO,UNIT=(3490,1),VALIDATE=YES,
$HASP882 VOLS=255
$HASP882 OFFLOAD2 212
$HASP882 OFFLOAD2 DSN=BACKUP.TJES2SPL.DMPLOD2,STATUS=DRAINED,
$HASP882 ARCHIVE=ONE,CRTIME=RESET,LABEL=SL,PROTECT=NO,
$HASP882 RETPD=30,TRACE=NO,UNIT=(3490,1),VALIDATE=YES,
$HASP882 VOLS=255
$HASP882 OFFLOAD3 213
$HASP882 OFFLOAD3 DSN=BACKUP.TJES2SPL.DMPLOD3,STATUS=DRAINED,
$HASP882 ARCHIVE=ONE,CRTIME=RESET,LABEL=SL,PROTECT=NO,
$HASP882 RETPD=30,TRACE=NO,UNIT=(3490,1),VALIDATE=YES,
$HASP882 VOLS=255
$HASP882 OFFLOAD4 214
$HASP882 OFFLOAD4 DSN=BACKUP.TJES2SPL.DMPLOD4,STATUS=DRAINED,
$HASP882 ARCHIVE=ONE,CRTIME=RESET,LABEL=SL,PROTECT=NO,
$HASP882 RETPD=30,TRACE=NO,UNIT=(3490,1),VALIDATE=YES,
$HASP882 VOLS=255
$HASP882 OFFLOAD5 215
$HASP882 OFFLOAD5 DSN=BACKUP.TJES2SPL.DMPLOD5,STATUS=DRAINED,
$HASP882 ARCHIVE=ONE,CRTIME=RESET,LABEL=SL,PROTECT=NO,
$HASP882 RETPD=30,TRACE=NO,UNIT=(3490,1),VALIDATE=YES,
$HASP882 VOLS=255
$HASP882 OFFLOAD6 216
$HASP882 OFFLOAD6 DSN=OSD.MIB.OFFLOAD4,STATUS=DRAINED,
$HASP882 ARCHIVE=ONE,CRTIME=RESET,LABEL=SL,PROTECT=NO,
$HASP882 RETPD=30,TRACE=NO,UNIT=(3390,1),VALIDATE=YES,
$HASP882 VOLS=255
$HASP882 OFFLOAD7 217
$HASP882 OFFLOAD7 DSN=OSD.MIB.OFFLOAD4,STATUS=DRAINED,
$HASP882 ARCHIVE=ONE,CRTIME=RESET,LABEL=SL,PROTECT=NO,
$HASP882 RETPD=30,TRACE=NO,UNIT=(3390,1),VALIDATE=YES,
$HASP882 VOLS=255
2. Display its characteristics
然后选一个你想用的OFFLOAD，查看一下它的具体指标
$DU,OFFLOAD(n)
$HASP882 OFFLOAD6 056
$HASP882 OFFLOAD6 DSN=OSD.MIB.OFFLOAD4,STATUS=DRAINED,
$HASP882 ARCHIVE=ONE,CRTIME=RESET,LABEL=SL,PROTECT=NO,
$HASP882 RETPD=30,TRACE=NO,UNIT=(3390,1),VALIDATE=YES,
$HASP882 VOLS=255
$HASP884 OFF6.JT 057
$HASP884 OFF6.JT STATUS=STARTABLE,CLASS=,CREATOR=,DISP=DELETE,
$HASP884 HOLD=,JOBNAME=,LIMIT=(0,*),NOTIFY=NO,RANGE=(J1,
$HASP884 999999),ROUTECDE=(),START=YES,SCHENV=,
$HASP884 SRVCLASS=,SYSAFF=(NONE),VOLUME=(,,,),WS=(CL/)
$HASP886 OFF6.ST 058
$HASP886 OFF6.ST STATUS=STARTABLE,CREATOR=,DISP=KEEP,
$HASP886 OUTDISP=(WRITE,HOLD),HOLD=,JOBNAME=,NOTIFY=NO,
$HASP886 RANGE=(J1,999999),ROUTECDE=(),START=YES,
$HASP886 VOLUME=(,,,),WS=(Q/),BURST=,FCB=,FLASH=,
$HASP886 FORMS=(,,,,,,,),LIMIT=(0,*),PLIM=(0,*),
$HASP886 PRMODE=(),QUEUE=8X,UCS=,WRITER=
$HASP883 OFF6.JR 059
$HASP883 OFF6.JR STATUS=STARTABLE,CLASS=,CREATOR=,HOLD=,
$HASP883 JOBNAME=,MOD=(CLASS=,HOLD=,ROUTECDE=,SYSAFF=),
$HASP883 NOTIFY=NO,RANGE=(J1,2147483647),ROUTECDE=(),
$HASP883 SCHENV=,SRVCLASS=,START=YES,SYSAFF=(NONE),
$HASP883 WS=(CL/)
$HASP885 OFF6.SR 060
$HASP885 OFF6.SR STATUS=STARTABLE,OUTDISP=(WRITE,HOLD,KEEP,
$HASP885 LEAVE),CREATOR=,HOLD=,JOBNAME=,MOD=(BURST=,
$HASP885 OUTDISP=,FCB=,FLASH=,FORMS=,HOLD=,PRMODE=,
$HASP885 QUEUE=,ROUTECDE=,UCS=,WRITER=),NOTIFY=NO,
$HASP885 RANGE=(J1,2147483647),ROUTECDE=(),START=YES,
$HASP885 WS=(Q,OUTD/),BURST=,FCB=,FLASH=,FORMS=(,,,,,,,
$HASP885 ),PRMODE=(),QUEUE=,UCS=,WRITER=
3. Modify OFFLOAD DSN and OUTDISP if neceseary
因为一般是OFFLOAD到TAPE上，如果你想改成DASD的话，需要修改UNIT，指定一下DSN，输出哪个CLASS的QUEUE，如果需要，OUTDISP也可以修改
$T OFF(n).ST,OUTDISP=
4. Start OFFLOAD
开始OFFLOAD
$S OFFLOAD7,TYPE=TRANSMIT
5. Stop OFFLOAD and close offload data set
OFFLOAD结束
确定是$S OFFLOAD7,TYPE=RECEIVE？呵呵
哎呀失误 应该是TYPE=TRANSMIT，您提醒的对