RSS Matters

Ready for Rainy days: Backing up files on tapes for mainframe users

By Dr.Karl Ho, Research and Statistical Support Services Manager

On July 12, 2001, the MVS batch system will undergo a system upgrade that may last up to 2 days.  If you are a mainframe user who submits job to the MVS batch system on a regular basis, this article provides ways to back up your files on tape cartridges.

1. To save a series of files from CMS or MVS to a tape, first write a file to a scratch tape.  Once a tape is assigned to your first file, you can use that same tape for storing other files.  To start from "scratch", use the IEBGENER program to save the file:

This IEBGENER program uploads a CMS program file to a tape.  Note that the file name on the tape is confined to no more 17 characters and the VOL=SER= parameter was intentionally left out. Click here to get a text copy of the program.

You can also copy an MVS file to the tape by modifying the SYSUT1 field.  Again, for the first copy, the VOL=SER= parameter has to be left out. 

2.   Once a file is successfully copied to a scratch tape, the IEBGENER output from Tape Management System (TMS) will return an assigned tape number as illustrated in the following partial output:

                    J E S 2  J O B  L O G  --  S Y S T E M  A C A D  --  N O D E  A C A D M V S

.
.
.
ICH70001I AC08     LAST ACCESS AT 11:57:15 ON FRIDAY, JUNE 15, 2001
IEF236I ALLOC. FOR AC08UP1
IEF237I DMY  ALLOCATED TO SYSIN
IEF237I JES2 ALLOCATED TO SYSPRINT
IEF237I 0E8B ALLOCATED TO SYSUT2
IEF237I JES2 ALLOCATED TO SYSUT1
IEF142I AC08UP1 - STEP WAS EXECUTED - COND CODE 0000
IEF285I   AC08.AC08UP1.JOB00538.D0000102.?             SYSOUT
IEF285I   USER.AC08.TESTMVS1.SPSMVS                    KEPT
IEF285I   VOL SER NOS= 300267.
IEF285I   AC08.AC08UP1.JOB00538.D0000101.?             SYSIN
IEF373I STEP/        /START 2001166.1419
IEF374I STEP/        /STOP  2001166.1420 CPU    0MIN 00.04SEC SRB    0MIN 00.00SEC VIRT    76K SYS   272K EXT       4K SYS    9392K
IEF375I  JOB/AC08UP1 /START 2001166.1419
IEF376I  JOB/AC08UP1 /STOP  2001166.1420 CPU    0MIN 00.04SEC SRB    0MIN 00.00SEC
DATA SET UTILITY - GENERATE                                                                       PAGE 0001
IEB352I WARNING : OUTPUT RECFM/LRECL/BLKSIZE COPIED FROM INPUT

PROCESSING ENDED AT EOD

Using this assigned tape, you can copy other files from your MVS disk or CMS disk to the tape.   Remember to label the files according to the order of uploading. The following IEBGENER program illustrates this process of copying an MVS SPSS portable file to the pre-assigned tape NNNNNN (e.g. 300267). Click here to get a text copy of the sample program.

Be reminded the VOL=SER= parameters refer to the physical location of the file. In the SYSUT1 line, it refers to the source file on the ACAD0N disk, where N should be from 0,2, 3 (e.g. ACAD03). If you are not sure if the copying is successful, use the following tapemap program to check the files on the tape:

//IDNNTMAP JOB (IDNN,2,3),'NAME',CLASS=B,PASSWORD=XXXXXXX,USER=IDNN
/*ROUTE PRINT UNTVM1.IDNN
/*ROUTE PUNCH UNTVM1.IDNN
//TAPEMAP PROC VOL=IDUNNO
//MAPPIT EXEC PGM=TAPEMAPS
//SYSUT1 DD LABEL=(1,BLP,EXPDT=98000),
// VOL=SER=&VOL,DISP=SHR,UNIT=TAPECR
//STEPLIB DD DSN=SYS2.A000.MVS.UTILS.LOAD,DISP=SHR
//SYSPRINT DD SYSOUT=A
//SYSUDUMP DD SYSOUT=A
// PEND
//MAP EXEC TAPEMAP,VOL=NNNNNN
//* Change nnnnnn to the TMS Volume Number