Starting in z/OS V1R13, the system resolver uses z/OS UNIX services in the resolver address space. Use of the z/OS UNIX services requires the resolver to have an OMVS segment associated with its user ID. If you do not define a user ID for the resolver with an associated OMVS segment, the resolver initialization fails and the TCP/IP stack initialization is not able to complete.
If you are migrating to z/OS V1R13 or z/OS V2R1 Communications Server and you already have a user ID for the system resolver procedure, no action is required if you meet either of these conditions:
- You explicitly defined an OMVS segment for the ID.
- An OMVS segment was created through the RACF automated assignment of unique z/OS UNIX identities support or through default OMVS segment support.
In contrast, if you are migrating to z/OS V1R13 or z/OS V2R1 Communications Server, and you do not have a user ID defined for the system resolver that has an associated OMVS segment, which provides access to z/OS UNIX services, you must take the following action. If you do not take action, the resolver initialization fails and the initialization of all TCP/IP stacks is delayed.
Steps to take:
- If you already have already assigned a user ID for the resolver started task but it does not have an OMVS segment, you must define an OMVS segment for the resolver user ID.
- If you do not have a resolver user ID, you must create one that includes an OMVS segment.
Note: These actions can be taken on any release at any time prior to upgrading.
The following information is an excerpt of the SEZAINST(EZARACF) sample job that you can use to define a user ID with an OMVS segment and assign it to the system resolver started procedure. You might need to modify the sample values that are specified in the commands for your environment. For example, the UID, Default Group, and Resolver user ID values are sample values.
//*=========================== RESOLVER ===============================
//* Create the userid and its OMVS Segment for the daemon and
//* add it to the STARTED Class which is activated in this job.
//* If you chose not to use the RACF STARTED Class,
//* the entry should be placed in the started procedures table ICHRIN03.
//RESOLVER EXEC PGM=IKJEFT01
//SYSTSPRT DD SYSOUT=*
//SYSTSIN DD *
ADDUSER RESOLVER DFLTGRP(OMVSGRP) OMVS(UID(42) HOME('/')) -
RDEFINE STARTED RESOLVER.* STDATA(USER(RESOLVER))
SETROPTS RACLIST(STARTED) REFRESH
SETROPTS GENERIC(STARTED) REFRESH
For information about defining and assigning a user ID for started procedures, see " Using Started Procedures" in z/OS Security Server RACF Security Administrator's Guide.
For information about defining an OMVS segment, see " RACF and z/OS Unix" in z/OS Security Server RACF Security Administrator's Guide.
For general information about starting the system resolver, see " Starting the resolver " in z/OS Communications Server IP Configuration Guide.