MacKinney Systems, Inc.

MacKinney Systems products using TCP/IP connections not having an OMVS RACF segment will receive delete Error Number 156 when attempting to start a TCP/IP connection.

An OMVS Segment has always been required for a z/OS program to use TCP/IP. On z/OS releases prior to 2.1, it was possible to supply default OMVS segment settings using the BPX.DEFAULT.USER facility, which allowed users without an OMVS segment to use TCP/IP. However, IBM has dropped the ability to use the BPX.DEFAULT.USER facility in z/OS 2.1. 

This change affects all MacKinney Systems customers who have been using the BPX.DEFAULT.USER facility for the following products:

  • JES Queue for Printers (JQP)
  • VTAM/Virtual Printer (VVP), only when the VVP LPD Server is enabled.


One solution available is:

Use RACF ALTUSER commands to manually assign each batch or STC user an OMVS segment:


This would add an OMVS segment to userid USERX, if it did not already exist, and assign it UID of "n". If the UNIXPRIV class's SHARED.IDS profile exists, then no users can have the same UID as another user, so "n" would also have to be unique.