DLBL
1. DLBL definition must be associated with a system or programmer
logical unit assignmentr previously made with an ASSGN command.
Specify the SYSxxx option on the first, or only, DLBL definition for a particular ddname. Many DLBL definitions may be associated
with the same logical unit. For example:
assgn sys100 b
dlbl ddl b cms test filel (sysl00 dlbl dd2 b cms test file2 (sys100 dlbl ddl cms test file3
is a valid command sequence.
2. The following special ddnames must be used to define DOS private
libraries, and must be associated with the indicated logical units: IJSYSSL IJSYSRL IJSYSCL Logical !Inii __ _ SYSSLB SYSRLB SYSCLB 1ibra£y Source statement
Relocatable
Core image
These libraries must be identified in order to perform librarian
functions (with the SSEBV, ESERV, DSERV r or RSERV commands) for
private libraries; or to link-edit or fetch modules or phases from
private relocatable or core image libraries (with the DOSLKED and
FETCH commands).
3. Each DOS file has a CMS file identifier associated with it by
default; the filename is always FILE and the filetype is always the
same as the ddname. For example, if you enter a DLBL command for a DOS file MOD.TEST.STREAM as follows:
dlbl test c dsn mod test stream
then you can refer to this OS data set as FILE TEST when you use
the STATE command: state file test When you enter a DLBL command specifying only a ddname and mode r as
follows:
dlbl junk a CMS assigns a file identifier of FILE JUNK Al to the ddname JUNK. 4. The FILEDEF command performs a function similar to that of the DLBL
command; you need to use the FILEDEF command in CMS/DOS only: • When you want to override a default ddname for an assembler
input or output file. • When you want to use the MOVEFILE command to process a file.
5. If you use the DUMMY operand, you must have issued an ASSGN command
specifying a device type of IGN
r or ignore, for the SYSxxx unit
specified in the DLBL command, for example, Section 2. CMS Commands 63

DLBL
assgn sys003 ign
dlbl test dummy (sys003 You must specify extent information
when you use the access method services control statements DEFINE SPACE, DEFINE DEFINE USERCATALOG, DEFINE CLUSTER (UNIQUE); or
when you use the IMPORT or IMPORTRA functions for a unique file.
When you enter the EXTENT option of the DLBL command, you are
prompted to enter the disk extents for the specified file. You must
enter extent information in accordance with the following rules: • You must specify the starting track number and number of tracks for
each extent, as follows:
This extent allocates 38 tracks, beginning with the 19th track, on a 3330 device. • All extents must begin and end on cylinder boundaries, regardless of
whetner the AMSERV file contains extent information in terms of
cylinders, tracks, or records. • Multiple extent entries may be entered
commas or on different lines. Commas
ignored.
on a single line separated by
at the end of a line are • Multiple extents for the same volume must be entered in numerically
ascending order; for example: 20 40 0, 600 80 These extents are valid for a 2314 device. • When you enter multivolume extents, you must specify the mode letter
and logical unit associated with each disk that contains extents; extents for each disk must be entered consecutively. For example:
assgn sy sOO 1 b
assgn sys002 c
assgn sys003 d
dlbl filel b (extent sys001 DMSDLB331R ENTER EXTENT SPECIFICATIONS: 100 60, 400 80, 60 40 d sys003 200 100 c svs002 400 100 c svs002 (null line)
specifies extents on disks accessed at modes B, C, and D. These
disks are assigned to the logical units SYS001, SYS002, and SYS003. Since B is the mode specified on the DLBL command line, it does not
need to be respecified along with the extent information. • A DASD volume must be mounted, accessed, and assigned for each disk
mode referenced in an extent.
When you are finished entering extent information, you must enter a
null line to terminate the DLBL command sequence. If you do not, an
error may result and you will have to reenter the DLBL command. If you
make any error entering the extents, you must reenter all the extent
information.
64 IBM VM/370 CMS Command and Macro Reference