JCL Basics What is JCL? Job Entry Subsystem Job Processing JCL Statements JCL Parameters JOB Statement Job Statement Parameters for Job Positional Parameters ACCT NAME Keyword Parameters MSGLEVEL MSGCLASS TYPRUN PRTY CLASS RESTART REGION TIME NOTIFY EXEC Statement EXEC Statement Positional Parameters PGM PROC Keyword Parameters COND PARM ADDRSPC DD statement DD statement DD Parameters SPACE SYSIN VOL DCB SYSOUT DSN UNIT DISP |
VOL parameter • It is used to specify a disk volume or specific tapes. • VOL parameter is used to identify the volume serial number of the device on which a given data set is to be written, or on which a data set resides. • It is used primarily for tape data sets, although they can also be used for disk. • A volume is the portion of the storage device served by one read/write mechanism. • Example: //DD1 DD DSN=REPORT,DISP=(NEW,CATLG), // VOL=SER=JCLUSR2,UNIT=SYSDA • To refer to a volume used by some prior DD statement use: VOL=REF=ddname • The UNIT and VOLUME parameters are used to create new data sets or to retrieve existing uncataloged data sets. For cataloged data sets no need to code the UNIT and VOL parameters because UNIT & VOL information is stored in the catalog. • When a new data set is written to disk, the VOL parameter should be coded only if there is a real need to identify a specific disk volume. When it is not coded, then Z/OS determines an accessible disk volume with sufficient space and writes to it. |