How to get a file from z/OS to a different z/OS without using FTP

I have a userid on a z/OS production system, which does not support FTP. To run my tests, I needed to get some files on to this system. Getting the files there was a challange.

The 3270 emulator has support for transferring files. It uses the IND$FILE TSO command to send data packaged as 3270 datastream As far as I can tell, this only works with data sets, not Unix files.

Creating a portable file from a data set.

You can package a data set into a FB Lrecl 80 dataset using the TSO XMIT (TRANSMIT) command.

Create a portable dataset from a Unix file.

On my home system I created a PAX dataset from a file in a Unix directory.

Use cd to get into the directory you want to package. If you specify a file name like /tmp/mypackage, the unpax will store the output in /tmp/mypackage which may not be where you want to store the data.

If you use relative directories such as ‘.’ it will unpax into a relative directory. I used the cd command to get into my working directory

pax -W "seqparms='space=(cyl,(10,10))'" -wzvf  "//'COLIN.ZOWE.PAX'" -x os390  myfile

You need both the single and double quotes around the data set name.

This created a data set with record format FB, and Lrecl 80.

A 360 MB file became a 426 CYL data set.

If you run out of space ( B37-04 abend). Delete the dataset before you reissue the pax command, otherwise the space parameters on the pax command are ignored; and increase the amount of space in the pax command.

I FTPed this down to my Linux machine in binary mode.

Send the file to the remote z/OS over 3270 emulator

Because FTP was not available I had to use the TSO facility IND$FILE. One of the options from the “file” menu was “File Transfer”.

You fill in details of the local file name, the remote data set name, and data set attributes.

In theory you need to be in TSO option 6 – where you can enter TSO commands, but when I tried this I kept getting “input field too small”. I had to exit ISPF and get into native TSO before the command worked.

The transfer rate is very slow. It sends one block at a time, and waits for the acknowledgement. With TCP/IP you can send multiple blocks before waiting for the ack, and use big blocks. For a 300MB file, I achieved 47KB per second with a 16000 block size – so not very high.

With IND$FILE, pick the biggest block size you can. I think it supports a maximum size of 32767. I got 86 KB/second with a 32767 block size with DFT mode.

For a dataset packaged with TSO XMIT

Use the TSO command RECEIVE INDSN(…) to restore the data set.

Un PAX the file to recreate it

On the production system, I use went into Unix, and used the cd command to get to the destination directory.

pax -ppx -rf  "//'COLIN.ZOWE.PAX'"