March 30
r 1979
dlbl newfile b (extent DMSDLB331R ENTER EXTENT SPECIFICATIONS: 100 400 80
r 60 r 60 40 d 2000 100 c
(null line)
If you make any errors issuing the DLBL command or extent information
r you must re-enter the entire command sequence.
IDENTIFYING EXISTING MULTIVOLUME When you issue a DLBL command to IdentIfy-an exIstIng multIvolume VSAM file, you must use the MULT option
of the DLBL command sequence:
dlbl old bl dsn ? (mult DMSDLB220R ENTER DATASET NAME: vsamtest.file DMSDLB330R ENTER VOLUME SPECIFICATIONS: c
r d
e
(null line) When you enter the DLBL command you should specify the mode letter for
the first disk volume on the command line. When you enter the MULT option you are prompted to enter additional specifications for the
remaining extents. In the above example, the data set has extents on
disks accessed as B-, C-, D-
r and E-disks. USING TAPE INPUT AND OUTPUT If you are using AMSERV for a function that requires tape input and/or output
r you must have the tape(s) attached to your virtual machine. The
valid addresses for tapes are 181, 182, 183, and 184. When referring to
tapes, you can also refer to them using their CMS symtolic names TAP1 r TAP2, TAP3, and TAP4. When you use AMSERV to create or read a tape, you supply the ddname
for the tape device interactively, after you issue the AMSERV command. You must also supply a LABELDEF command for tape label checking before
you issue the AMSERV command. To indicate to AESERV that you are using
tape for input or output
r you must use the TAPIN or TAPOUT option to
specify the tape device being used:
labeldef tapedd fid filename ••• amserv export (tapout 181
In this example
r the
virtual address 181.
output from an EXPORT function is CMS prompts you to enter the ddname: DMSAMS367R ENTER TAPE OUTPUT DDNAMES: to a tape at
After you enter the ddname (TAPEDD in this example) for the tape file, AMSERV begins execution. AMSERV in CMS treats all tape files as having standard labels. The
LABELDEF command is required because the CMS/DOS routine that performs
the tape open needs label inforaation for standard labelled tapes. See the description of the LABELDEF command in Section 7 for further
information. The filename you specify on the LAEELDEF command should be
the same one you use to reply to the access method service message that
requested you to supply the tape's ddnames. However, the LABELDEF command must be issued before the AMSERV command. If you only want the
tape labels skipped, but not checked, enter a LABELDEF with no
parameters other than filename. 204 IBM VM/370 eMS User's Guide

Pg. of GC20-1819-2 Rev March 30, 1979 by Supp. SD23-9024-1 for 5748-118 Tapes used for input must always EOPl labels or they are rejected by need to contain VOLl labels because
volume serial number and have the
However, blank tapes should not be
routine tries to read the tape.
contain standard VOL1, RDR1, and CftS AftSERV. Output tapes do not the user is prompted to enter a VOLl label written if he wants.
used for output because the open When you create a tape file using AMSERV under eMS, CMS writes a label
file preceding each output data file. When CftS AMSERV is used to read
this same file, it checks the RDRl and VOLl labels using the LABELDEP co •• and you provide before it reads the data file. If you want to read
the tape on a real OSjVS system, however, you must use the LABEL=SL as a parameter on the data definition (DD) card for the tape. Section 10. Using Access Method Services and VSAft 204.1