Placing a switch port online or offline

Use the VARY SWITCH(ssss,pp[-pp][,pp[-pp]]...),{DCM=OFFLINE[,UNCOND]|ONLINE} command to place a switch port online or offline to dynamic channel path management. Invoking this command for a switch port will also cause the specific managed device paths to be varied online or offline. An offline request will cause the managed channel paths to be removed from the control units connected to the managed CHPIDs at the specified ports. The VARY SWITCH command is routed to all systems in the logical partition cluster to ensure that all systems run with the same configuration of managed channel paths.

This command affects only managed device paths. Nonmanaged paths must be varied online or offline separately.

Note: If you specify DCM=OFFLINE or =ONLINE for a logical partition cluster spanning multiple logical channel subsystems, you must issue the command from a system at the z990 V1R4 exploitation support level or higher. For example, if systems A and B have z990 V1R4 compatibility support and are running in CSS 0, while systems C and D have exploitation support and are running in CSS 1, you must issue the DCM= command from system C or system D.

The format of the VARY SWITCH command is:

V SWITCH(ssss,pp[-pp][,pp[-pp]]...),DCM=OFFLINE[,UNCOND]
                                   ,DCM=ONLINE

ssss: specifies the switch device number.
pp[-pp] [,pp[-pp]]: specifies the switch port address or address list.
DCM=OFFLINE[,UNCOND]: specifies that the switch port is to be varied offline to dynamic channel path management. If UNCOND is specified, then the UNCOND option will be passed to the VARY PATH commands that are invoked as a result of this VARY SWITCH command. See Placing an I/O Path or Paths Online or Offline.
DCM=ONLINE: specifies that the switch port is to be varied online to dynamic channel path management.

Example 1:

To vary port 60 of switch B000 offline on the two systems in a logical partition cluster, enter on system MVS1:

VARY SWITCH(b000,60),DCM=OFFLINE

The response from this command will show how it ran on both systems, MVS1 and MVS2:

MVS1 IEE633I SWITCH B000, PORT 60, DCM STATUS=OFFLINE
             ATTACHED NODE = 003990.0CC.IBM.XG.000000000006 
             THE FOLLOWING DEVICE PATHS ARE ONLINE THROUGH THIS PORT: 
             (0220,58) 

MVS2 IEE633I SWITCH B000, PORT 60, DCM STATUS=OFFLINE 
             ATTACHED NODE = 003990.0CC.IBM.XG.000000000006 
             THE FOLLOWING DEVICE PATHS ARE ONLINE THROUGH THIS PORT: 
             (0220,58)

These messages show that the command ran on both system MVS1 and MVS2. The fact that these messages are identical shows that these systems are configured identically — the preferred configuration when using dynamic channel path management.