DLBL • If you enter they must be
ignored.
more than one mode letter and logical unit
separated by commas; trailing commas on
on a line,
a line are • maximum of nine disks may be specified you do not need to specify
them in alphabetical order. You must enter a null line to terminate the
finished entering extents; if not, an error may
reenter the entire command sequence.
command when
result and
you are
you must
In order to display the volumes on which all multivolume data sets
reside, the following commands are issued:
DLBL (MULT) or QUERY DLBL MULT The following information concerning multiple volume datasets is
provided: MODE LOGUNIT The DOS filename or OS ddname.
The CMS disk mode identifying one of the disks on which the
dataset resides.
The DOS logical unit specification (SYSxxx). This operand
will be blank for a data set defined while in CMS/OS environment; that is, the SET DOS ON command had not been
issued at OLBL definition time.
If no OLBL definitions with multiple volume specifications are
active, the following is issued: OMSOLB324I NO USER DEFINED MULTS IN EFFECT USING CATALOGS: There are two special ddnames you must use to catalog and job catalog:
IJ SYSCT IJSYSUC identifies the master catalog when you initially define it
(using AMSERV), and when you begin a terminal session. You should use the PERM option when you define it. You must assign the logical unit SYSCAT to the disk on which
the master catalog resides. If you are redefining a master
catalog that has already been identified, you may omit the SYSCAT option on the DLBL command line.
identifies a job catalog to be used for subsequent AKSERV jobs
or VSAM programs. Any programmer logical unit may be used to assign a job
catalog. 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 OLBL
command sequence illustrates the use of catalogs:
assgn syscat c
dlbl ijsysct c dsn mastcat (perm syscat
identifies the master catalog, MASTCAT, for the terminal session.
66 IBM VM/370 CMS Command and Macro Reference

DLBL
assgn sysO 1 0 d
dlbl ijsysuc d dsn mycat (perm sys010 identifies the job (user) catalog, MYCAT, for the terminal session.
assgn sys100 e dlbl intest1 e dsn test case (vsam sys100 identifies a VSAM file to be used in a program. It is cataloged in the
job catalog, MYCAT. assgn sys101 f
dlbl cat3 f dsn testcat {cat ijsysct sys101 identifies an additional user catalog, which has an entry in the master
catalog. Since a job catalog is in use, you must use the CAT option to
indicate that another catalog, in this case the master catalog, should
be used.
dlbl infile f dsn test input (cat cat3 sys101 identifies an input file cataloged in the user catalog TESTCAT, which
was identified with a ddname of CAT3 on the DLBL The selection of a VSAM catalog for AMSERV jobs and VSAM programs
running in CMS is summarized in Figure 7. IS THE CAT OPTION SPECIFIED ON THE
DLBL COMMAND ? NO I IS THERE A
DLBL ACTIVE FOR IJSYSUC ? NO USE THE
MASTER CATALOG YES YES USE THE CATALOG DEFINED BY
THAT DDNAME USE THE JOB CATALOG Figure 1. Determining Which VSAM Catalog to Use Section 2. CMS Commands 67