Recycling z/OS UNIX System Services (z/OS UNIX)

Use the MODIFY OMVS command to recycle z/OS UNIX System Services. This is an alternative to re-IPLing the the system in order to reinitialize the z/OS UNIX System Services environment. This command should be used only on a limited basis when complete reinitialization and reconfiguration are required. Prior to issuing MODIFY OMVS to initiate a shutdown, you should review the information about shutdown in z/OS UNIX System Services Planning.

The MODIFY OMVS,SHUTDOWN command completely disables z/OS UNIX services. IBM® strongly recommends that an installation perform the following steps prior to issuing the command:
  1. Attempt to dry up batch and interactive workloads. Once a shutdown request is accepted, jobs that subsequently attempt to connect to z/OS UNIX services for the first time will be delayed until restart occurs; jobs that are already connected to z/OS UNIX services (dubbed) will be sent terminating signals and will end abruptly.
  2. Follow recommended procedures to quiesce applications and subsystem workloads using z/OS UNIX services. This will allow subsystems such as DB2®, CICS®, and IMS™, and applications such as SAP, LOTUS DOMINO, NETVIEW, and WEBSPHERE to be quiesced in a more controlled manner than would occur if simply using this command. Use the D OMVS,A=ALL command to determine which applications, if any, require quiescing.
  3. Shut down TCP/IP and all TCP/IP applications in the manner that TCP/IP recommends.
  4. Shut down any colony PFS address spaces. This could potentially include NFS and DFS.
 
F OMVS{,SHUTDOWN}    
      {,RESTART[,OMVS=(xx,yy)]}
            

The parameters are:

OMVS
The name of the job.
SHUTDOWN
Request that the system shut down the UNIX services environment, which includes quiescing all running UNIX services work on a given system.
RESTART
Request that the system restart the UNIX services environment which has shut down successfully.
OMVS
Specifies the parmlib member or members (BPXPRMxx) to use to locate the parmlib statements to configure the z/OS UNIX kernel.

If the OMVS parameter is not specified, the BPXPRMxx member used on the previous start of OMVS is processed again, with any updated contents taking effect.

Example 1:

To shut down the UNIX services environment, enter:
F OMVS,SHUTDOWN
The following highlighted console message will be displayed when the shutdown request is accepted:
BPXI055I OMVS SHUTDOWN REQUEST ACCEPTED
If a shutdown request cannot be accepted, the following console message will be displayed:
BPXI057I OMVS SHUTDOWN REQUEST REJECTED
If a shutdown request is delayed because of blocking jobs or processes, the following console message will be displayed when the delay exceeds a finite time interval:
BPXI064E OMVS SHUTDOWN REQUEST DELAYED