The FTP server received a REST (restart) command from the FTP client as part of a sequence of commands to transfer data to the FTP server. The REST command instructs the server that the current file transfer is a resumption of an interrupted file transfer. The server file is a named pipe. File transfer to a named pipe cannot be restarted.
>>> rest 10
350 REST command accepted, parameter 10.
>>> PORT 9,2,1,3,4,43
200 Port request OK.
>>> STOR /tmp/my.fifo
504 Restart not allowed for named pipes.
Command: The FTP server rejects the file transfer.
Notify the system programmer.
If the server application that reads from the named pipe can tolerate reading the same data more than once from the named pipe, instruct the user to transfer the entire file to the named pipe again instead of attempting to restart the file transfer.
Otherwise, identify the last data read by the server application, and provide a new file or data set to the FTP client starting from that point. Have the user transfer the new file or data to the named pipe.
See the system programmer response.
z/OS® Communications Server TCP/IP: FTP