Disconnecting your mount point

Use the unmount command to break the connection between the mount point on your client and the server (that is, to unmount). You must have superuser authority to issue the unmount command.

Note: The same unmount function can also be performed using the UNIX automount facility. When the automount facility is used to manage remote NFS mount points, the NFS client user could experience ESTALE/EIO errors if the automounter unmounts the accessed mount point when the time limits specified by the automount duration and delay parameters have been exceeded. For additional information on the UNIX automount facility, see z/OS UNIX System Services Planning and z/OS UNIX System Services Command Reference.

Figure 1 illustrates the syntax of the TSO UNMOUNT command. For more information about the UNMOUNT command, see z/OS UNIX System Services Command Reference.

Figure 1. TSO UNMOUNT command syntax operands

UNMOUNT  FILESYSTEM(file_system_name)
NORMAL | DRAIN | IMMEDIATE | FORCE | RESET

where

FILESYSTEM(file_system_name): Specifies the name of the file system to be removed from the file system hierarchy. file_system_name specifies the file_system_name exactly as it was specified when the file system was originally mounted. You can enclose file_system_name in single quotes, but they are not required.
NORMAL|DRAIN|IMMEDIATE|FORCE|RESET: NORMAL: Specifies that if no user is accessing any of the files in the specified file system, the unmount request is processed. Otherwise, the system rejects the unmount request. NORMAL is the default option.
DRAIN: Specifies that the system is to wait until all uses of the file system have ended normally before the unmount request is processed or until another UNMOUNT command is issued.
Note: UNMOUNT can be specified with IMMEDIATE to override a previous unmount DRAIN request for a file system. If this is used in the foreground, your TSO/E session waits until the unmount request has completed. The attention request key (usually ATTN or PA1) will not end the command.

IMMEDIATE: Specifies that the system is to unmount the file system immediately. Any users accessing files in the specified system receive failing return codes. All data changes to files in the specified file system are saved. If the data changes to files cannot be saved, the unmount request fails.
Note: UNMOUNT of an NFS mount point (regardless of soft or hard mount option) with NORMAL, DRAIN, or IMMEDIATE may fail with the return code of EBUSY if the z/OS NFS client determines that there are ongoing NFS requests to the NFS server. The UNMOUNT receiving EBUSY can have the file system unmounted immediately with FORCE, at the risk of data loss.

FORCE: Specifies that the system is to unmount the file system immediately. Any users accessing files in the specified file system receive failing return codes. All data changes to files in the specified file are saved, if possible. If the data changes cannot be saved to the files, the unmount request continues and data is lost.
Note: You must issue an UNMOUNT IMMEDIATE request before issuing UNMOUNT FORCE. Otherwise, UNMOUNT FORCE fails.

RESET: A reset request stops a previous unmount DRAIN request.

The following example unmounts the file system NFSC_001 normally:

UNMOUNT FILESYSTEM('NFSC_001')

The following example forces an unmount of the file system NFSC_001. You must issue an UNMOUNT IMMEDIATE before you can issue an unmount FORCE command.

UNMOUNT FILESYSTEM('NFSC_001') IMMEDIATE
UNMOUNT FILESYSTEM('NFSC_001') FORCE

If you receive a “No Such File or Directory” message, the z/OS system operator can also unmount your workstation from the server. If this happens before you try to unmount, you get a “No such file or directory” error message.