Stopping the z/OS NFS client

The z/OS NFS client is started when the z/OS UNIX file system is initialized and is persistent until z/OS UNIX is stopped. To stop the z/OS NFS client gracefully the system operator can use the modify operator command omvs,stoppfs specifying the NFS client, as follows:

f omvs,stoppfs=NFS

If this command fails to gracefully shut down the z/OS NFS client, the operator can force an abnormal termination using the operator command cancel with the z/OS NFS client address space name; for example:

cancel  mvsnfsc

It is imperative and necessary to stop the z/OS NFS client gracefully so it can save its important data (RPC transaction ID) for the subsequent restart.

Attention: The destruction of the z/OS NFS client address space can cause unpredictable abnormal z/OS UNIX address space behavior. If a z/OS UNIX process tries to access the NFS client data during its address space destruction, then an OC4 protection exception in the z/OS UNIX BPXVCLNY load module can occur.

To bring down the NFS client during shutdown, follow these steps:

Stop the NFS client. It runs in a colony address space; to terminate it, enter either of the following:
- f omvs,stoppfs=nfs
- CANCEL <nfsv> (if STOPPFS did not work)
Stop TCPIP, because it is a registered blocker of OMVS SHUTDOWN.
Terminate z/OS UNIX System Services
```
f omvs,shutdown
```