Communicating with the device manager address space

Use the MODIFY DEVMAN command to communicate with the device manager address space to display information or to request a specified service. Use this command only at the direction of the system programmer.
 
F DEVMAN,{DUMP}
         {REPORT}
         {RESTART} 
         {END(taskid)}
         {ENABLE(feature) }
         {DISABLE(feature)}
         {?|HELP}

The following are brief descriptions of the parameters.

DUMP
Captures a diagnostic dump of the device manager address space, including the dataspace that contains device manager CTRACE records.
Note: The device manager CTRACE component name is SYSDMO. To connect the device manager to an output writer, use the command TRACE CT,ON,COMP=SYSDMO.
REPORT
Provides basic information about the current activity and module levels for the device manager address space.
Notes:
  1. Start of changeIf Multiple Incremental FlashCopy is enabled by installing the PTF for the enablement APAR OA45412 followed by a system IPL, the output of the F DEVMAN,REPORT command displays the MULTIPLE INCREMENTAL FLASHCOPY: CHANGE RECORDING V2 status.

    If Multiple Incremental FlashCopy is disabled by issuing the SET DEVSUP=xx command with MULTINCRFLC=NO in the DEVSUPxx member of PARMLIB, the MULTIPLE INCREMENTAL FLASHCOPY: CHANGE RECORDING V2 status will not appear in the output of the F DEVMAN,REPORT command.

    For more information, see Example 4 under Examples.

    End of change
  2. Start of changeIf Easy-Tier Copy Temperature function for software defined storage is enabled by setting EASYTIERHINTS=YES in the DEVSUPxx member of PARMLIB, the output of the F DEVMAN,REPORT command displays the EASY-TIER FOR SOFTWARE DEFINED STORAGE status.

    If Easy-Tier Copy Temperature function for software defined storage is disabled by issuing the SET DEVSUP=xx command with EASYTIERHINTS=NO in the DEVSUPxx member of PARMLIB, the EASY-TIER FOR SOFTWARE DEFINED STORAGE status will not appear in the output of the F DEVMAN,REPORT command.

    For an example of the output of the F DEVMAN,REPORT command, see Example 5 under Examples. For more information about the EASYTIERHINTS keyword, see z/OS MVS Initialization and Tuning Reference.

    End of change
RESTART
Terminates the device manager address space and restarts the device manager in a new address space. The system allows any subtasks that are active in the device manager address space at the time of the restart to finish processing. The time allowed for subtask completion is determined by using the average time taken by previous subtasks. The system abnormally ends any subtasks that do not complete in time before it restarts the address space.
Notes:
  1. Use RESTART to avoid IPL when you install software. You can install most device manager APARs by refreshing LLA (F LLA,REFRESH), and then restarting the device manager (F DEVMAN,RESTART).
  2. You can end and not restart the device manager address space by using the CANCEL DEVMAN command. When you end the address space in this way, you must restart the device manager with the DEVMAN cataloged procedure.
END(taskid)
Terminates the subtask identified by taskid. The F DEVMAN,REPORT command displays the taskid for a subtask.
ENABLE(feature)
Enables an optional feature. The supported features are named as follows:
REFVTOC
Use ICKDSF to automatically REFORMAT/REFVTOC a volume when it expands.
DATRACE
Capture dynamic allocation diagnostic messages.
REFUCB
Enables the automatic REFUCB function of the Device Manager. When the REFUCB feature is enabled the system automatically updates the UCB when device support software detects that a DSS COPY or RESTORE or ICKDSF REFORMAT NEWVTOC operation has changed either the volser or the VTOC location. In the case of a volser or VTOC location change, the system invokes the DEVMAN REFUCB service on each system in the sysplex that has REFUCB enabled.
  • If the device is ONLINE, REFUCB issues a VARY ONLINE, UNCONDITIONAL command, which updates both the volser and VTOC location in the UCB.
  • If the device is OFFLINE, no action is taken.
PPRCSUM
Enables the PPRCSUM feature of the Device Manager, which means using message IEA075I instead of IEA494I to report devices that transition to PPRC suspended state. The PPRCSUM feature significantly reduces the volume of messages that are written to the console when devices in a PPRC relationship are suspended due to a PPRC freeze. If you enable PPRCSUM, the system will issue one or more IEA075I messages to summarize the PPRC state for all devices in the control unit.

Warning: If GDPS or other PPRC monitoring software is active, make sure that you have the appropriate version of this software before enabling PPRCSUM.

Note that if the PPRCSUM feature is enabled or disabled after IPL, one device in every control unit must be varied online to activate the feature.

QUERYFC:NUM
Enables Query FlashCopy Capability (QUERYFC) with the specified number NUM (1-9999) of requests. The NUM variable represents a UNIT of work for requests issued at any given time when an ADRDSSU COPY command is invoked. A conservative value for UNIT is 64, which is specified by the F DEVMAN,ENABLE(QUERYFC:64) command, indicating that 64 QUERYFC channel programs are issued in parallel. When the first 64 complete, another set of 64 QUERYFC channel programs are added, and the sequence repeats until all volumes in the Storage Group are queried.

When QUERYFC is enabled, the F DEVMAN,REPORT command verifies that the UNIT value is specified correctly via the NUM parameter. The command also reports the maximum number of observed QUERYFC requests. If many tasks are running in parallel, a large number of QUERYFC requests is typical.

DISABLE(feature)
Disables one of the following optional features:
  • REFVTOC
  • DATRACE
  • REFUCB
  • PPRCSUM

    When PPRCSUM feature is disabled, the system issues a PPRC suspend notification message (IEA494I) for each individual device in the control unit.

    Note that if the PPRCSUM feature is enabled or disabled after IPL, one device in every control unit must be varied online to activate the feature.

  • QUERYFC

    Disables QUERYFC, which allows all Query FlashCopy Capability (QUERYFC) requests to be issued simultaneously. This is the default, which does not limit users to a fixed number of requests. For example, the F DEVMAN,DISABLE(QUERYFC) command does not limit the number of QUERYFC requests, allowing all requests to go to the controller simultaneously.

HELP|?
Displays the DEVMAN MODIFY command syntax.

Examples

Example 1:
The DEVMAN REPORT display has the following format:
 FMID:  HDZ1A10                                                
 APARS: NONE                                                   
 OPTIONS:  REFVTOC                                             
 SUBTASKS:                                                     
 JOBNAME  STARTED   SERVICE   UNIT  STATUS               ID    
 ------------------------------------------------------------  
 DEVMAN   15.42.32  REFVTOC   3700  SUBTASK RUNNING      0001
Where:
FMID
Displays the FMID level of DEVMAN.
APARS
Displays any DEVMAN APARs that are installed (or the word NONE).
OPTIONS
Displays the currently enabled options (in the example, REFVTOC is enabled).
SUBTASKS
Lists the status of any subtasks that are currently executing.
Example 2:
The MODIFY DEVMAN,HELP command displays the DEVMAN MODIFY syntax, as follows:
 ?|HELP          - display devman modify command parameters         
 REPORT          - display devman options and subtasks              
 RESTART         - quiesce and restart devman in a new address space
 DUMP            - obtain a dump of the devman address space        
 END(taskid)     - terminate subtask identified by taskid           
 DSFTRACE((TP01))- define ICKDSF trace point(s) ((TP01)(TP02)(etc)) 
 ENABLE(feature) - enable an optional feature                       
 DISABLE(feature)- disable an optional feature                      
 -------------------------------------------------------------------
 Optional features:                                                 
 REFVTOC         - automatic VTOC rebuild                           
 REFUCB          - Allow UCB update after DSS volume restore
 PPRCSUM         - DASD summary message support DATRACE  
                 - dynamic allocation diagnostic trace              
 QUERYFC:num     - Enable QUERYFC with num(1-9999) requests  
 QUERYFC         - Disable QUERYFC to allow all QUERYFC requests
Example 3:
The F DEVMAN,ENABLE(QUERYFC:64) command displays the following example text:
 DMO0012I DEVICE MANAGER ENABLE QUERYFC(64)                     
 f devman,report                                                
**** DEVMAN ****************************************************
* FMID:  HDZ1D10                                               *
* APARS: OA39569  UA63192                                      *
* OPTIONS:                                                     *
*           QUERYFC : UNIT = 0064 TOTAL = 0000                 *
* NO SUBTASKS ARE ACTIVE                                       *
**** DEVMAN ****************************************************
Start of change
Example 4:
When Multiple Incremental FlashCopy is enabled, the F DEVMAN,REPORT command displays the following example text: 
**** DEVMAN ****************************************************
* FMID:  HDZxxxx                                               *
* APARS: AA46256                                               *
* OPTIONS:  NONE                                               *
* HPF FEATURES DISABLED:  NONE                                 *
* MULTIPLE INCREMENTAL FLASHCOPY: CHANGE RECORDING V2          *
* NO SUBTASKS ARE ACTIVE                                       *
**** DEVMAN ****************************************************

Note that the APARS field displays only DEVMAN APARs or PTFs; it does not display APARs or PTFs that are not in the DEVMAN component.

End of change
Start of change
Example 5:
When Easy-Tier Copy Temperature function for software defined storage is enabled, the F DEVMAN,REPORT command displays the following example text: 
**** DEVMAN *************************************************
* FMID:  HDZxxxx                                            *
* APARS: AA45241                                            *
* OPTIONS:  NONE                                            *
* HPF FEATURES DISABLED:  NONE                              *
* EASY-TIER FOR SOFTWARE DEFINED STORAGE                    *
* NO SUBTASKS ARE ACTIVE                                    *
**** DEVMAN *************************************************
End of change
Parent topic: MODIFY command