Load module transfer with FTP

As long as your FTP client and FTP server are both at the z/OS® Communications Server V2R10 or later, you can use FTP to transfer MVS™ load modules between load libraries on different hosts or the same host. MVS load modules transferred, using z/OS Communications Server V2R10 or later support, are executable on the target system. A load module can be specified by its real name or by one of its alias names, and in either case, all aliases are transferred with each load module. Load module transfer (LMTR) is also supported for proxy transfer, in which case all three hosts (client, primary server, and secondary server) must be z/OS Communications Server V2R10 or later.

Load module transfer processing (at z/OS V1R2 Communications Server or later) makes use of the IEBCOPY system utility, which must be available on both the origin and destination hosts.

The following FTP file transfer commands will properly transfer MVS load modules:
  • get
  • mget
  • mput
  • mvsget
  • mvsput
  • put
Because of the special requirements of MVS load modules, there are some additional restrictions:
  • Do not transfer nonexecutable load modules, or load modules of size 0 or undefined size. Unpredictable results will occur.
  • The current working directory on both the client and the server must be the source or destination load library. A load library is a PDS or PDSE with RECFM=U.
  • Only member names can be specified. No fully qualified names can be specified.
  • File rename is not supported on load module transfer.
  • Load modules can be transferred only between the same types of libraries. For example, PDS to PDSE transfer is not allowed.
  • If load modules are being sent to or from the z/OS FTP client, the client must be started from one of the following environments:
    • TSO terminal session
    • TSO REXX
    • TSO batch
    • TSO background
    • Unix System services terminal session
  • A load module loading from a temporary data set will always be a REPLACE operation, overwriting existing members. LMTR is not performed in STOU mode (the user has toggled SUNIQUE on).
  • There is no prompting on mput and mget subcommands. All files that match the mask provided are transferred.
In most cases where load module processing cannot be performed, including failure to abide by the restrictions given above, FTP completes the file transfer using normal processing. Any load modules transferred with normal processing are not executable on the target system.
For the examples shown below, the following assumptions are made:
  • The contents of load library USER.LINKLIB are: 
      Name     Prompt        Alias-of     Size      TTR     AC   AM   RM  
 EZACDOPN                           0000D268   00160F   01    31  ANY 
 EZAFTPLC                           000E3758   00001B   01    31  ANY 
 FTP                     EZAFTPLC   000E3758   00001B   01    31  ANY 
 OPING                   EZACDOPN   0000D268   00160F   01    31  ANY
  • USER1.TESTLIB is a PDS with RECFM=U.
The following example is a sample session involving a load module transfer with debug/trace on. (For clarity, user input is shown offset to the left and notes are contained within // characters.) 
   220-FTPD1 IBM FTP CS V1R2 at MVS097, 21:16:25 on 2003-01-16.                
   220 Connection will not timeout.                                             
   NAME (9.67.43.61:USER1):                                                      
user1                                                                         
   >>> USER user1                                                               
   331 Send password please.                                                    
   PASSWORD:                                                                    
                                                                              
                                                                              
   >>> PASS                                                                     
   230 USER1 is logged on.  Working directory is "USER1.".                      
   Command:                                                                     
cd 'user.linklib'                                                             
   >>> CWD 'user.linklib'                                                       
   250-The working directory may be a load library
   250-The working directory "USER.LINKLIB" is a partitioned data set  //1//
   Command:                                                                     
lcd 'user1.testlib'                                                           
   Local directory might be a load library      //1//                                
   Local directory name set to partitioned data set USER1.TESTLIB               
   Command:                                                                     
get oping                          
   >>> XLMT PDS 0  oping                        //2//
   250 PDS 53864 - send next command for load module transfer //2//                    
   >>> PORT 9,67,43,65,4,41                                                        
   200 Port request OK.                                                           
   >>> RETR oping                                                                 
   125-Transferring load module                 //2//                                  
   125 DCB 32760 32760                          //2//                                  
                       IEBCOPY MESSAGES AND CONTROL STATEMENTS  //3//        PAGE     1
                                                                                  
                                                                                
   IEBCOPY  FMID HDZ11D0  SERVICE LEVEL UW90570  DATED 19990520 DFSMS             
           1.5.0   MVS SP6.0.8 HBB6608  CPU 9672                                  
   USER1    OS390R5  OS390R5  16:20:59 TUE 16 NOV 1999 PARM=''                    
     STANDARD DD NAMES- SYSIN    SYSPRINT SYSUT1   SYSUT2   SYSUT3                
           SYSUT4                                                                 
   OVERRIDING DD NAMES- SYS00158 SYS00159 SYS00157 SYS00156 SYSUT3                
           SYSUT4                                                                 
   VL GETMAIN REQUESTED 280K TO 1M BYTES.  OBTAINED 1M.                           
                                                                                  
       COPY      OUTDD=SYS00156,INDD=((SYS00157,R))                               
   ORIGINAL PDS  (BEFORE UNLOAD) WAS RECFM=U    BLKSIZE=32760 LRECL=0             
           KEYLEN=0 OPTCD=X'20' UCBTYPE=X'3010200F' INDC=X'00'                    
   ALLOCATED 2 CONTIGUOUS BUFFERS EACH 111K BYTES.  WORK AREA HAS 757K            
           BYTES AVAILABLE.                                                       
                                                                               
   COPYING FROM PDSU  INDD=SYS00157 VOL=                                         
           DSN=SYS99320.T162100.RA000.USER1.TEMPXLMT.H01                         
             TO PDS  OUTDD=SYS00156 VOL=CPDLB1 DSN=USER1.TESTLIB                 
   CONTROL TABLE IS 20 BYTES LONG.  WORK AREA HAS 757K BYTES AVAILABLE.          
   ALLOCATED SECOND BUFFER OF 745K BYTES.  FIRST BUFFER IS NOW 221K              
           BYTES.  WORK AREA HAS 11974 BYTES AVAILABLE.                          
   FOLLOWING MEMBER(S) LOADED FROM INPUT DATA SET REFERENCED BY SYS00157         
   EZACDPIN HAS BEEN SUCCESSFULLY LOADED                        //4//                 
   OPING    HAS BEEN SUCCESSFULLY LOADED                        //4//                 
   2 OF 2 MEMBERS LOADED FROM INPUT DATA SET REFERENCED BY SYS00157              
   THERE ARE 135 UNUSED TRACKS IN OUTPUT DATA SET REFERENCED BY SYS00156         
   THERE ARE 23 UNUSED DIRECTORY BLOCKS IN OUTPUT DIRECTORY                      
   RELEASED 1016K ADDITIONAL BYTES.                                              
   END OF JOB - 0 WAS HIGHEST SEVERITY CODE                                      
   250 Transfer completed successfully.                                          
   63084 bytes transferred in 0.005 seconds.  Transfer rate 12616.80 Kbytes/sec. 
   Command:
In this next example, the user attempts to transfer a load module and rename the load module. As this is not supported, load module processing will exit and normal processing will take over. The transferred load module will not be executable on the target system. 
cd 'user.linklib'                                                            
   >>> CWD 'user.linklib'                                                      
   250-The working directory may be a load library
   250-The working directory "USER.LINKLIB" is a partitioned data set
   Command:                                                                    
lcd 'user1.testlib'                                                          
   Local directory might be a load library                                     
   Local directory name set to partitioned data set USER1.TESTLIB              
   Command:                                                                    
get oping ping                                                               
   Load module transfer does not support load module rename //5//                   
   >>> PORT 9,67,43,66,4,41                                                        
   200 Port request OK.                                                        
   >>> RETR oping                                                              
   125 Sending data set USER.LINKLIB(OPING)                                    
   250 Transfer completed successfully.                                        
   61984 bytes transferred in 0.190 seconds.  Transfer rate 326.23 Kbytes/sec. 
   Command:
Notes:
  1. When a cd or lcd subcommand is performed, the user will be notified if the new current directory is eligible for load module transfer processing. If this message or reply is not seen when changing to a directory, load module transfer will not be attempted.
  2. There are additional flows between the client and server for load module transfer.
  3. The IEBCOPY system utility is invoked by FTP as part of load module transfer processing. The IEBCOPY messages are written on the client invocation for a client and to syslogd for a server in the following situations:
    • An error exists.
    • No error exists and DEBUG FSC(2) is on.
    DUMP 31 can be used to verify that IEBCOPY is invoked when a FTP load module transfer is started.
  4. The actual load module and all of its aliases are transferred, even though (in this case only) the alias was specified by the user.
  5. When load module transfer processing cannot be performed, the user is warned and the transfer might be completed using normal processing. The data set USER.TESTLIB(PING) is not executable on the client system.