DL BL There are two special ddnames you must use to
identify a VSAM master catalog and job catalog:
IJ SYSCT IJ SYSUC identifies the master catalog, both when you initially define
it (using AMSERV) and when you begin a terminal session. You should use the PERM option when you define it.
identifies a job catalog to be used for subsequent AMSERV jobs
or VSAM programs. Only one VSAM catalog is ever searched when a VSAM function is
performed. If a job catalog is defined, you may override it by using
the CAT option on the DLBL command for a data set. The following DLBL
command sequence illustrates the use of catalogs:
dlbl ijsysct c dsn mastcat (perm
identifies the master catalog, MASTCAT, for the terminal session.
dlbl ijsysuc d dsn mycat (perm
identifies the job (user) catalog, MYCAT, for the terminal session.
dlbl intestl e dsn test case (vsam
identifies a VSAM file to be used in a program. It is cataloged in the
job catalog, MYCAT. dlbl cat3 dsn testcat (cat ijsysct
identifies an additional user catalog, which has an entry in the master
catalog. Since a job catalog is in use, you must use the :AT option to
indicate that another catalog, in this case the master catalog, should
be used.
dlbl infile e dsn test input (cat cat3
identifies an input file cataloged in the user catalog TEST:AT, which
was identified with a ddname of CAT3 on the DLBL command.
The selection of a VSAM catalog for AMSERV jobs and VSAM programs
running in CMS is summarized in Figure 7.
If the DLBL command is issued with no operands, the current DLBL
definitions are displayed at your terminal:
ddnamel devicel (fnl ftl fml [datasetnamel]]
ddnamen devicen (fnn ftn fmn (datasetnamen]] DMSDLB220R ENTER DATA SET NAME: This message is displayed when you use the DSN? form of the DLBL
command. Enter the exact DOS or as data set name. DMSDLB320I NUMBER OF DISK ENTRIES RECORDED This message indicates that nine volumes have been specified for a data set, which is the maximum allowed under CMS. 70 IBM VM/370 CMS Command and Macro Reference

DLBL DMSDLB321I MAXIMUM NUMBER OF EXTENTS RECOP.DED This message indicates that 16 extents on a single disk or minidisk
have been specified for a VSAM data space, catalog, or unique data
set. This is the maximum number of extents allowed on a minidisk
or disk. DMSDLB322I DDNAME 'ddname' NOT FOUND; NO CLEAR EXECUTED This message indicates that the clear function was not performed
because no DLBL definition is in effect for the ddname. DMSDLB323I {MASTERIJOB} CATALOG DLBL CLEARED
This message indicates that either the master catalog or job
catalog has been cleared as a result of a clear request. You also receive this message if you issue a DLBL * CLEAR command,
and any DLBL definition is in effect for IJSYSCT or IJSYSUC that
was not entered with the PERM option. DMSDLB330R ENTER VOLUME SPECIFICATIONS: This message prompts you to enter volume specifications for
existing multivolume VSAM files. (See "Identifying Multivolume VSAM Extents" in the appropriate usage section.) DMSDLB331R EXTENT SPECIFICATIONS: This message prompts you to enter the data set extent or extents of
a new VSAM data space, catalog or unique data set. (See "Specifying VSAM Extent Information" in the appropriate usage
section., DMSDLB001E NO FILENAME SPECIFIED RC=24 DMSDLB003E INVALID OPTION 'option' RC=24 DMSDLB005E NO '{CATIBUFSP}' SPECIFIED RC=24 DMSDLB023E NO FILETYPE SPECIFIED RC=24 DMSDLB04AE INVALID MODE 'mode' RC=24 DMSDLB050E PARAMETER MISSING AFTER DDNAME RC=24 DMSDLB065E joption' OPTION SPECIFIED TWICE RC=24 DMSDLB066E 'option' AND 'option' ARE CONFLICTING OPTIONS RC=24 DMSDLB010E INVALID PARAMETEF 'parameter' RC=24 DMSDLBOq6E INVALID DDNAME 'ddname' RC=24 DMSDLB10QS VIRTUAL STORAGE CAPACITY EXCEEDED RC=104 DMSDLB221E INVALID DATA SET NAME RC=24 DMSDLB301E 'SYSxxx' NOT ASSIGNED FOR DISK 'fm' RC=36 DMSDLB302E NO SYSXI! OPERAND ENTERED RC=24 DMSDLB304E INVALID OPERAND VALUE 'value' RC=24 DMSDLB305E INCOMPLETE EXTENT RANGE RC=24 DMSDLB306E SYStII NOT ASSIGNED FOR 'IGNORE' RC=36 DMSDLB307E CATALOG DDNAME 'ddname' NOT FOUND RC=24 DMSDLB30AE 'mode' DISK IN {CMSINON-CMS} INVALID FOR {NON-CMSICMS} DATASET RC=24 Section 2. CMS Commands 71