ACCESSING THE IBM 9672 OS/390 SYSTEM VIA TCP/IP

Introduction
Remote Logins Via Telnet
File Transfers Via FTP
Replacing, Renaming, and Deleting Datasets Using FTP

Introduction

The installation of TCP/IP (Transmission Control Protocol/Internet Protoc ol) on the University of South Carolina IBM 9672 mainframe running OS/390 allows users on other Internet hosts to: (1) do remote logins to several systems that are running on the 9672 via the TCP/IP TELNET software, and (2) do file transfers to and from MVS DASD volumes via the TCP/IP FTP software). Following are instructions for connecting to USC's MVS machine (mvs.sc.edu) for remote login and file transfers.

NOTE: While this discussion assumes you are using a command-based TCP/IP interface, Macintosh and Windows TCP/IP graphic interfaces will provide similar capabilities. Instructions included here are specific to the MVS TCP/IP server; instructions for interaction from your local host's TCP/IP client are generic. Refer to the documentation accompanying your machine's TCP/IP software package(s) for specific local instructions.

Attention VM/CMS Users
For information on accessing the USC VM/CMS mainframe system refer to the handout CMS. For information on the TCP/IP client running on VM/CMS and used in accessing other computer systems on the Internet, refer to the handouts FTP and TELNET.

Remote Logins Via Telnet

To logon to the 9672 from another internet machine, you should connect to the hostname:

MVS.SC.EDU

Please note that you will need to emulate an IBM mainframe terminal; if you are attempting the connection from a non-IBM mainframe, the standard TELNET software used to initiate remote logins will not give you full-screen access. You will need to use a version of TELNET such as TN3270 which emulates a 3270 device. 3270 emulations of telnet are available from the Computer Services Center, 777-1800.

If your connection to MVS is successful, you will be placed at the USC CSD application menu, which displays systems accessible from MVS: USCAN, LUIS, IMS, TSO, and USCADM.

USCAN

USCAN is USC's On-Line Library Catalog System. USCAN runs under the NOTIS, Inc. software and is a public access system; no userid or password is required. Enter a 2 on the commandline at the bottom of the screen to connect.

To exit from USCAN, back out to the main menu, and enter the command:

STOP

LUIS

LUIS is Clemson University's On-Line Library Catalog System. LUIS runs under the NOTIS, Inc. software and is a public access system; no userid or password is required. Enter a 5 on the commandline at the bottom of the screen to connect.

To exit from LUIS, back out to the main menu, and enter the command:

STOP

IMS

IMS is IBM's Information Management System which supports USC's administrative databases. Access to IMS is by authorized userid and password.

To initiate a connection to IMS, enter a 3 (or a 6 to use the test release of IMS) on the commandline at the bottom of the screen.

To exit from an IMS session, clear the screen and enter /RCL to return to your local session.

TSO

TSO is IBM's Time Sharing Option system and is used internally at Computer Services for program development. TSO is available to some administrative users outside Computer Services for file transfer purposes. Userid and password are required, and the userid must have TSO authorization. To connect, enter 4 userid (where userid is your userid). If you are not authorized to use TSO, the message Userid uuuuuuu not authorized to use TSO will be displayed; press PF3 to return to the USC CSD application menu.

To exit from a TSO session, return to the main panel, and enter LOGOFF at the commandline.

USCADM

The USCADM system allows USC faculty, staff, and students to request CMS computer ids, and to reset CMS and IMS passwords. Access is authorized by USC id and USC PIN number. For more information on USCADM, refer to the handout USCADM.

File Transfers Via FTP

This connection will allow you to retrieve ( GET ) datasets you have previously created on MVS as DASD files, and to store ( PUT ) additional datasets on MVS.

Note to LAN Workplace Users

When using the command-based ftp client that is supplied with LAN Workplace for DOS or Windows to connect with the MVS ftp server, you should enter the following command *once* before GETting (retrieving) or PUTting (storing) files: remotedir The 'remotedir' command will return the following response: ftp> The remote host does NOT support sub-directories. After that, any GET or PUT commands will work correctly. When using the Rapid Filer GUI FTP client that is supplied with LAN Workplace for Windows to connect to the MVS FTP server, select 'MVS' from the 'Remote Operating System' menu before clicking on the 'Open' button. To send a SITE command in Rapid Filer, you should connect to the MVS server and, while the MVS directory is highlighted in the bottom window, pull down the 'View' menu and select 'Enable Protocol Window'. Type the desired SITE command in the 'Command to Send' box and then click on 'Send'.

Note to Macintosh Fetch Users

Problems have been noted using Fetch releases prior to 3.0.1 and TCP/IP connections to MVS. To enable successful transfers from MVS to a Macintosh using Fetch 3.0.1 it is important to note that a special setting must first be enabled: From the CUSTOMIZE menu select PREFERENCES, then MISC; X in the box by TREAT MYSTERY ITEMS AS FILES to enable this option. This fix will allow you to download files from MVS using Fetch. If you are running a previous version of Fetch that does not include this option, an upgrade is available (free to persons affiliated with an educational institution) at the URL: http://www.dartmouth.edu/pages/softdev/fetch.html Copies are also available from Computer Services, 777-1800.

Using the TCP/IP command file transfer software ( FTP or its equivalent on your system), connect to the host:

MVS.SC.EDU

Attention VM/CMS Users
NOTE: If you are connecting to USC's MVS machine from USC's VM/CMS machine, you may abbreviate the hostname to: MVS

Enter your userid and password when prompted.

Your working directory will be your USC RACF security userid followed by a period.

For example, if your userid is N123456, your default working directory when you FTP to MVS will be:

N123456.

NOTE: Anonymous ftp service is not available on the MVS FTP server. If you need to access datasets on MVS DASD using your FTP client, you should request a userid and password from Computer Services: http://www.sc.edu/ars/IMSforms.html .  If you only need temporary FTP access to the MVS server, request a temporary userid and password from the person who created the files. This person who creates the MVS dataset must permit the temporary userid access to the dataset.

Changing your Foreign Working Directory

In command-based TCP/IP clients, the commands CD and DIR are used to Change Directories and list DIRectory contents; graphic-based interfaces will allow you to accomplish the same functions by selecting menu options. The following discussion explains the directory organization on the MVS machine.

You can change your foreign working directory so that you are working with a subset of your MVS datasets. If you specify a string following the CD command that is not delimited by single quotes, that string is appended to the current working directory.

For example, if your current working directory is N123456. and you enter:

CD TEST1

N123456.TEST1.

Note that a DIR command issued at this point will display file information for all MVS datasets beginning with

N123456.TEST1.

N123456.TEST1

DIR TEST1*

CD ..

JOHNDOE.PROJ1.RAW1.

JOHNDOE.PROJ1.

To override the existing directory rather than append to the directory qualifiers you previously issued, specify the new directory name in single quotes in the CD command. For example,

CD 'T5544444.DATA'

MVS DASD files that have been migrated off the active DASD volumes by the Hierarchical Storage Manager can be retrieved via FTP. (See the CMS handout DISK for a more complete discussion of HSM.) The DIR command lists the volume name of Migrated for datasets that currently migrated off DASD volumes. See the note under the discussion of File Retrieval below for more information on retrieval of migrated datasets.

File Retrieval

In command-based TCP/IP clients, the commands GET and MGET are used to retrieve single and multiple files from the current directory; graphic-based interfaces will allow you to accomplish the same functions by selecting menu options. The following discussion explains the directory organization on the MVS machine to assist you in retrieving files.

Dataset names requested in GET and MGET commands are assumed to be prefixed by the current working directory name unless delimited by single quotes. At initial login, your default directory is your userid followed by a period, for example:

N123456.

GET MYFILE local.filename

N123456.MYFILE

Attention VM/CMS Users
NOTE: If you are retrieving datasets to your VM/CMS account specifying a filename only, the default filetype will be: $DEFAULT

If your current working directory is N123456.TEST1. and you enter: GET MYFILE local.filename the MVS FTP server will attempt to retrieve the dataset:

N123456.TEST1.MYFILE

N123456.TEST1.MYFILE1 N123456.TEST1.MYFILE2 N123456.TEST1.MYFILE3

MGET MYFILE*

For example: if your current working directory prefix is:

N123456.

GET 'T999999.DATA.FILE' local.filename

T999999.DATA.FILE

Text files should be retrieved in the default ASCII mode, but binary files such as executable modules should be retrieved in binary mode (enter the FTP command BINARY to enable binary transfers).

NOTE: When you attempt to retrieve a file which is listed as a migrated dataset, a request is sent to HSM to recall the migrated file. The following message will be sent to your local host session:

150-Waiting for recall of dataset USERID.DATA.SET.NAME

     Server not responding, closing connection.
     Connection with MVS terminated
     Abnormal  condition  during  inter-VM  communication  (VMCF  Rc=0
        User=TCPIP)

If you wish to retrieve a number of migrated datasets, you might want to first submit a batch job to recall them by whatever method/system you would normally submit a batch job to the MVS system. For example, a DSUTIL job submitted from VM/CMS that requests each migrated DSN in a LISTDS statement would cause the datasets to be recalled (see Figure 1 for an example of this job setup). Once the job has completed, you can retrieve the files to your local host via FTP.

 
 
 
 
   ---------------------------------------------------------------------- //MYJOB JOB(N1234567),SMITH,USER=N123456,PASSWORD=????????
   /*ROUTE PRINT VM.N123456
   // EXEC DSUTIL
   //SYSIN DD *
    LISTDS DSN=N123456.PROJ1.JAN92
    LISTDS DSN=N123456.PROJ1.FEB92
    LISTDS DSN=N123456.PROJ1.MAR92
   //
 
  Figure 1: Sample DSUTIL job setup to recall migrated datasets
  See CMS handout DSUTIL for a complete explanation of DSUTIL commands.
 
 ----------------------------------------------------------------------

Copying Files to MVS

In command-based TCP/IP clients, the command PUT is used to copy files from your local host to MVS; graphic-based interfaces will allow you to accomplish the same functions by selecting menu options. The following discussion explains the directory organization on the MVS machine to assist you in copying files to MVS.

Note to First Time Users

If you receive the message: Unable to create dataset xxx.xxx for STOR command when attempting to PUT a file to MVS, you must first signon to the CMS mainframe system and submit a batch job to authorize your userid to write to MVS. The following dummy job will signal the system to authorize your userid to write to MVS and submit batch jobs from CMS after a 30-minute interval. If you have questions, contact Computer Services at 777-1800. //UTIL JOB (xxxxxxxx),'PGMNAME',TIME= (,15),//MSGLEVEL=(1,1),MSGCLASS=A,USER=userid, // PASSWORD=???????? /*ROUTE PRINT VM.userid /*JOBPARM LINES=99 // EXEC DSUTIL //SYSIN DD * DSSLIST DSN=userid Create a file on CMS, add these lines to it, substituting your batch account number for 'xxxxxxxx' in the first record, and your userid for 'userid' in records 2, 4, and 8. SAVE and SUBMIT the file (enter these commands on the commandline). When you submit the job, the system will trigger an automated permission procedure that will allow you to submit batch jobs and to PUT files via FTP. This procedure takes about 30 minutes, after which time you can FTP files to MVS.

When copying files from your local host to MVS, specification of dataset names works exactly as previously described for retrieving files from MVS. If your current working directory is N123456. and you enter the command:

PUT MYNEW.DAT NEW.DATA

Prior to PUTting files to MVS, however, you must issue a SITE command from FTP to indicate the file's attributes on MVS. SITE parameters in FTP are similar to parameters coded when creating MVS files through IBM Job Control Language (JCL). At a minimum, you must specify the specific UNIT for the dataset you wish to store on MVS (for example, ACADA, HEDDA, ADMDA, etc.).

When using a non-CMS (i.e. DOS, Mac OS, unix) ftp client to copy a sequential ascii file to MVS DASD, the default file structure for the DASD file is LRECL=128, BLKSIZE=6144, and RECFM=FB. If any records in your file are longer than 128 bytes, those records in the DASD file will be truncated to 128 bytes. To avoid data loss caused by this truncation, you MUST use the SITE command to specify the LRECL, BLKSIZE, and RECFM of the MVS DASD file before transferring the file.

Attention Non-IBM Systems Users
NOTE: From some non-IBM systems, the SITE command must be prefixed by the QUOTE command in order for the SITE parameters to pass through directly to the remote FTP server.

A typical SITE command used in creating new MVS dataset via FTP follows:

SITE FILE=SEQ LR=80 BLK=9040 REC=FB TR PRI=3 SEC=1 U=ACADA

Following is an explanation of valid SITE parameters:

 
FILEtype=filetype
 
    where valid filetype values are:
 
                   SEQ  Sequential or partitioned datasets on DASD
                   JES  Remote job submission and retrieval
 
LRecl=nnn
    where nnn is the logical record length (LRECL)
 
BLocKsize=nnnn
    where nnnn is the block size (BLKSIZE)
 
RECfm=format
    where format is:  F, FA, FB, FBA, FBM, FM, U, V, VA, VB, VBA, VBM,
                      or VBS
 
TRacks
    To indicate that space should be allocated in tracks
 
CYlinders
    To indicate that space should be allocated in cylinders
 
PRImary=nnn
    where nnn indicates  the number of primary space  units (tracks or
       cylinders)
 
SECondary=nnn
    where nnn indicates the number of secondary space units (tracks or
       cylinders)
 
DIrectory=nnn
    where  'nnn'  indicates  the  number of  directory  blocks  to  be
       allocated for the directory of a PDS
 
Unit=unit_type
    where unit type indicates  the DASD volume group  ( ACADA,  ADMDA,
       HEDDA, etc.)

Replacing, Renaming, and Deleting Datasets Using FTP

Access to MVS DASD files via ftp is controlled by RACF (Resource Access Control Facility), the security system for all MVS and VM/CMS resources. If an MVS datasetname begins with your userid, you are the RACF owner of the data set, and you have the highest level of access allowed, ALTER access. To access a non-public MVS file belonging to another user, you must have been given some level of access by that user. (For information on setting access levels using the batch utility DSUTIL command PERMIT, enter the CMS command HANDOUTS DSUTIL. For information on setting access levels using the interactive CMS command PERMIT, enter HELP USC PERMIT from CMS.)

Access levels recognized by RACF are:

 
READ - Authority only to read the dataset,  not to modify it.  You can
        retrieve a copy  of a file using  the ftp GET command  if your
        userid has been permitted READ access.
 
UPDATE - Authority to read or modify a  dataset,  but not to delete or
        rename it.   You can retrieve a copy  of the file with the GET
        command or replace the entire contents  of a file with the ftp
        PUT command.

Replacing Datasets

To replace, or update, a dataset you own (or a dataset to which you have UPDATE access), you simply use the ftp PUT command with the existing MVS data set name; this action will write over the original file. Some ftp clients may require that you include a REPLACE option in the command to confirm that you wish to replace the contents of the MVS file with a copy of your local file.

Renaming Datasets

Suppose your working directory is N123456.APPLES., and the DIR command lists the following:

 
     GOLDEN.DEL
     GRANNY.SMITH
     ROME

RENAME ROME RED.DEL

Deleting Datasets

When using an ftp program to connect to the MVS system, you can use the ftp DELETE command to delete an MVS file. From any working directory, you can issue a DELETE command against a specific dataset by specifying its complete RACF DSN in single quotes, for example:

DELETE 'N123456.MYFILE.RAW'

DELETE RAW

The ftp MDEL can be used to delete multiple files: the asterisk (*) is the wildcard character in MDEL commands. The MDEL command should always be used with caution: as a safeguard when using MDEL, it is wise to first issue a DIR command against the identical string that you plan to use with MDEL to list those files which would be deleted.

Attention VM/CMS Users
WARNING: Many ftp clients have a safeguard built-in to the MDEL command, requiring confirmation for each dataset before deleting it. However, the VM/CMS ftp client does NOT request that you confirm each file before deleting: the CMS ftp client just goes ahead and deletes all files that match. So if you are using the VM/CMS ftp client to access MVS, beware!

Suppose your MVS userid is N123456, and you have the following datasets on DASD:

 
     N123456.PROJ1.DAT1
     N123456.PROJ1.DAT2
     N123456.PROJ1.DAT3
     N123456.PROJ1.DAT4
     N123456.PROJ2
     N123456.PROJ2.DAT1
     N123456.PROJ2.DAT2
     N123456.PROJ2.DAT3

N123456.

MDEL PROJ1*

MDEL PROJ1.*

 
     DAT1
     DAT2
     DAT3
     DAT4

MDEL *

DAT1 DAT2

MDEL *

 
     PROJ2
     PROJ2.DAT1
     PROJ2.DAT2

MDEL PROJ2*