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HP OpenVMS DCL Dictionary

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This example shows a Fast Path assignment made by a user.

Normally, the User Preferred CPU ID matches the current preferred CPU ID. The reason for the mismatch in the above display is because CPU 2 was stopped. The port was previously assigned to CPU 2. But when CPU 2 was stopped, the operating system moved the port assignment from CPU 2 to CPU 1.

If CPU 2 were started, the operating system would assign the device to the User Preferred CPU.


Disk DSA0:, device type RAM Disk, is online, mounted, file-oriented
  device, shareable, available to cluster, error logging is enabled,
  device supports bitmaps (no bitmaps active).
 Error count                 0  Operations completed               47
 Owner process              ""  Owner UIC                    [SYSTEM]
 Owner process ID     00000000  Dev Prot          S:RWPL,O:RWPL,G:R,W
 Reference count             2  Default buffer size               512
 Total blocks             1000  Sectors per track                  64
 Total cylinders             1  Tracks per cylinder                32
Volume label           "TST0"  Relative volume number              0
 Cluster size                1  Transaction count                   1
 Free blocks               969  Maximum files allowed             250
 Extend quantity             5  Mount count                         1
 Mount status           System  Cache name    "_$252$DUA721:XQPCACHE"
 Extent cache size          64  Maximum blocks in extent cache     96
 File ID cache size         64  Blocks currently in extent cache    0
 Quota cache size            0  Maximum buffers in FCP cache      404
 Volume owner UIC     [SYSTEM]  Vol Prot  S:RWCD,O:RWCD,G:RWCD,W:RWCD
 Volume Status:  ODS-2, subject to mount verification, file high-water
     marking, write-back caching enabled.
Disk $252$MDA0:, device type RAM Disk, is online, member of shadow set DSA0:.
 Error count                 0  Shadow member operation count    128
 Allocation class          252
Disk $252$MDA1:, device type RAM Disk, is online, member of shadow set DSA0:.
 Error count                 0  Shadow member operation count    157
 Allocation class          252


This example shows that a write bitmap exists for a shadow set, and that no write bitmap is active. If a shadow set supports write bitmaps, "device supports bitmaps" is displayed along with either "bitmaps active" or "no bitmaps active". If the device does not support write bitmaps, no message pertaining to write bitmaps is displayed.


Device         BitMap     Size         Percent of
Name            ID       (Bytes)       Full Copy
DSA12:         00010001   652          11%


This example shows a SHOW DEVICE/BITMAP display. You can find out the ID of each write bitmap on a node with this command. The /BITMAP qualifier is similar to the /REBUILD qualifier in that neither can be combined with most other SHOW DEVICE qualifiers. The SHOW DEVICE/BITMAP display can be brief or full; brief is the default. Use the /FULL qualifier to view the entire display.

If no bitmap is active, no bitmap file ID is displayed. The phrase "no bitmaps active" is displayed.


Displays information on devices served by the mass storage control protocol (MSCP) server on this node. The /SERVED qualifier is required.




The SHOW DEVICES/SERVED command displays information about the MSCP server and the devices it serves. This information is used mostly by system managers. The following message displays when the user issues a SHOW DEVICE/SERVED command when the tape server is not loaded:

%SHOW-E-TMSCPNOTLD, TMSCP-Server code not loaded



This qualifier displays the information displayed by all of the qualifiers listed below except the /OUTPUT qualifier.


Displays the number of transfer operations completed, sorted by the size of the transfers, and the number of MSCP operations that have taken place since the MSCP server was started.


Use with the /PAGE=SAVE and /SEARCH qualifiers to specify a search string that must match the search string exactly and must be enclosed with quotation marks (" ").

If you specify the /EXACT qualifier without the /SEARCH qualifier, exact search mode is enabled when you set the search string with the Find (E1) key.


Use with the /PAGE=SAVE and /SEARCH qualifiers to specify the type of highlighting you want when a search string is found. When a string is found, the entire line is highlighted. You can use the following keywords: BOLD, BLINK, REVERSE, and UNDERLINE. BOLD is the default highlighting.


Displays the names of the processors that have MSCP served devices on line. The System Generation utility (SYSGEN) command MSCP/HOST determines how many hosts in the OpenVMS Cluster can connect to the MSCP server at one time.


Redirects output from your terminal to the specified file. If you do not specify a file, or if you do not use this qualifier, output is sent to SYS$OUTPUT.


/NOPAGE (default)

Controls the display of device information on the screen.

You can use the following keywords with the /PAGE qualifier:

CLEAR_SCREEN Clears the screen before each page is displayed.
SCROLL Displays information one line at a time.
SAVE[= n] Enables screen navigation of information, where n is the number of pages to store.

The /PAGE=SAVE qualifier allows you to navigate through screens of information. The /PAGE=SAVE qualifier stores up to 5 screens of up to 255 columns of information. When you use the /PAGE=SAVE qualifier, you can use the following keys to navigate through the information:

Key Sequence Description
Up arrow key, Ctrl/B Scroll up one line.
Down arrow key Scroll down one line.
Left arrow key Scroll left one column.
Right arrow key Scroll right one column.
Find (E1) Specify a string to find when the information is displayed.
Insert Here (E2) Scroll right one half screen.
Remove (E3) Scroll left one half screen.
Select (E4) Toggle 80/132 column mode.
Prev Screen (E5) Get the previous page of information.
Next Screen (E6), Return, Enter, Space Get the next page of information.
F10, Ctrl/Z Exit. (Some utilities define these differently.)
Help (F15) Display utility help text.
Do (F16) Toggle the display to oldest/newest page.
Ctrl/W Refresh the display.

The /PAGE qualifier is not compatible with the /OUTPUT qualifier.


Displays information about the resources available to the MSCP server for use in processing I/O requests for the devices it serves.

You make these resources available by using the following system parameters: MSCP_BUFFER, MSCP_CREDITS, MSCP_LOAD, and MSCP_SERVE_ALL.

Refer to OpenVMS Cluster Systems or SYSGEN online help for more information.


Use with the /PAGE=SAVE qualifier to specify a string that you want to find in the information being displayed. Quotation marks are required for the /SEARCH qualifier, if you include spaces in the text string.

You can also dynamically change the search string by pressing the Find key (E1) while the information is being displayed. Quotation marks are not required for a dynamic search.



       MSCP-Served Devices on BIAK 28-MAY-2001 13:48:01.32

                                             Queue Requests
Device:           Status     Total Size     Current    Max    Hosts
   $11$DUA8       Online        2376153           0      2        6
   $11$DUA9        Avail        2376153           0      0        0
   $11$DUA10      Online        2376153           0      2        8
   $11$DUA11      Online        2376153           0      2        7
   $11$DUA13      Online        2376153           0      2        7
   $11$DUA14       Avail        2376153           0      0        0
   $11$DUA16       Avail        2376153           0      0        0
   $11$DUA17       Avail        2376153           0      0        0
   $11$DUA18      Online        2376153           0      1        4
   $11$DUA19      Online        2376153           0      4        7
   $11$DUA20      Online        2376153           0      1        7
   $11$DUA21      Online        2376153           0     17       12

This example shows the output generated by the command SHOW DEVICES/SERVED. The first column in the display shows the names of the devices that are served by the MSCP server. The second column shows the status of the devices. The third column shows the size, in blocks, of the device.

The Queue Requests columns show the number of I/O requests currently awaiting processing by that device and the maximum number of I/O requests that have ever been concurrently awaiting processing by that device. The last column in the display shows the number of hosts that have the device on line.


       MSCP-Served Devices on BIAK 28-MAY-2001 13:49:52.41
Request Count:
     0-7:   951154        32-39:     2168        88-103:     1618
    8-15:   197224        40-55:     2543       104-127:      189
   16-23:   137707        56-71:     8343
   24-31:      982        72-87:      141

Operations Count:
   ABORT             0   ERASE          22772   READ        1042206
   ACCESS            0   FLUSH              0   REPLACE           0
   AVAILABLE       611   GET COM STS        0   SET CTL CHR     176
   CMP CTL DAT       0   GET UNT STS  4026024   SET UNT CHR    3630
   CMP HST DAT       0   ONLINE           427   WRITE        259953
   Total       5355799

This example shows the information displayed by the SHOW DEVICES/SERVED/COUNT command. The numbers to the left of the colon (:), separated by a hyphen (-), are the size, in pages, of the requests. The numbers to the right of the colon are the number of requests of that size that have been processed by the MSCP server.

The section of the display headed by the label Operations Count shows the number of times the MSCP server has performed the MSCP operations listed. In the example, this MSCP server has performed 176 set-controller-characteristics (SET CTL CHR) operations, and has performed 3630 set-unit-characteristics (SET UNT CHR) operations.


       MSCP-Served Devices on BIAK 28-MAY-2001 13:51:32.01
Resources:         Total      Free      In Use
    Buffer Area:     400       400           0
    I/O Packets:       0         0

                 Current   Maximum
    Buffer Wait:       0         0

This example shows the information displayed by the SHOW DEVICES/SERVED/RESOURCE command. The Total column shows the total number of pages in the buffer area and in the number of I/O-request packets set aside for use by the MSCP server. The Free column shows the number of pages in the buffer and the number of I/O-request packets that are available for use.

The In Use column shows the number of pages within the buffer area that are in use.

The line labeled Buffer Wait shows the number of I/O requests that are currently waiting for buffer space to become available for their use, and the maximum number of I/O requests that have waited concurrently to obtain a buffer.


       MSCP-Served Devices on BIAK 28-NOV-2001 13:54:41.99
                                           Queue Requests
Host:              Time of Connection      Current    Max   Devices
    IPL31       25-MAY-2001 21:44:06.44          0      1         0
    DELAND      25-MAY-2001 21:44:09.98          0      1         0
    HEAVEN      25-MAY-2001 22:03:15.67          0      7        10
    VIVA        26-MAY-2001 09:44:11.96          0      1         0

This example shows the information displayed by the SHOW DEVICES/SERVED/HOST command. The first column contains the names of the hosts that have class drivers connected to the MSCP server. The next column contains the times at which these connections were made.

The columns under the heading Queue Requests show the number of requests the MSCP server currently has outstanding for I/O activity on the devices it serves, the maximum number of such requests that have been outstanding at one time, and the number of MSCP server devices that the listed hosts have on line.


       MSCP-Served Devices on HEN  3-DEC-2001 09:09:08.49
                                         Queue Requests
Device:          Status    Total Size    Current   Max  Hosts
   254$DJB1       Avail             0          0     0      0
   254$DUA2      Online       1216665          0     0      1
   254$DUA4006    Avail             0          0     0      0

      TMSCP-Served Devices on HEN  3-DEC-2001 09:09:08.74
                                         Queue Requests
Device:          Status     Position     Current   Max  Hosts
   90$MUA7        Avail             0          0     0      0
   90$MUA8        Avail             0          0     0      0
   90$MUA50      Online          3804          0     0      0

This example displays the output of the SHOW DEVICES/SERVED command from a node that has both MSCP server and TMSCP server devices. In the display, the third column for MSCP server disk devices shows the size of the disk device. The same column for TMSCP server device shows the location where each tape is currently positioned.


Indicates the node where output from a DECwindows application will be displayed.


SHOW DISPLAY [display-device]



Refers to the display-device parameter specified with the SET DISPLAY command. If you are directing application output to multiple workstations in the same session, you can use logical names to point to each workstation. Using the SHOW DISPLAY command, you can specify this logical name as the display-device parameter to see where application output will be displayed.

If you do not specify a display-device string, the logical name DECW$DISPLAY is used.


DECwindows gives you the ability to run applications across a network. The SET DISPLAY command enables you to direct the output of client applications across the network to an alternate workstation (X display server) for viewing. For example, the SET DISPLAY command allows you to:
  • Redirect the output from local client applications to a remote workstation for display.
  • Redirect the output from remote client applications to your local workstation for display. Although the application runs on another processor, it looks the same as any other application running locally on your workstation.

By running applications on a remote processor for local display on your workstation, you can take advantage of larger computers that might be better suited to a specific computing task. By default, applications running on your workstation are displayed on your workstation.

You use the SET DISPLAY command to direct the output from applications to other workstations. The SHOW DISPLAY command lets you see where the output from these applications will be displayed.

Sample output from the SHOW DISPLAY command looks like the following:

    Device:    WSA2:  [super]
    Node:      0
    Transport: LOCAL
    Server:    0
    Screen:    0

The description of each item follows:

  • Device is your workstation device. A new WSAn device is created each time you use the SET DISPLAY/CREATE command.
  • Node is the network system on which the output from applications is displayed. When you are running and displaying applications on your node, Node is 0, which is the standard shorthand notation for representing your node.
  • Transport refers to the mechanism, for example, DECNET or LOCAL, that passes information between the application---the client---and the server. The server sends input from the user to the application and output from the application to the display.
  • Server is 0.
  • Screen is 0.

On DECwindows workstations, the Session Manager creates a default workstation device for use by DECwindows processes (like DECterm). When you use the SET HOST command to connect to a remote node, no workstation device is created for that process and DECW$DISPLAY is not defined. You must specifically create new display devices with the SET DISPLAY/CREATE command.

If no definition for DECW$DISPLAY exists, entering the SHOW DISPLAY command returns an error.

Qualifiers to the SHOW DISPLAY command enable you to display properties related to the display device and extract authorization information, as described in the following sections.

Displaying Named Properties (Alpha only)

Named property values are designed to store configuration information associated with the display device, such as the network address of a session manager. By using the /ALL and /SYMBOLS qualifiers, you can display all the named properties related to the display device and use them to define one or more global symbols.

See the description of the SET DISPLAY command for more information.

Extracting Authorization Information (Alpha only)

If the display device is connected to a workstation that is using either Magic Cookie or Kerberos access control, you can use the /EXTRACT qualifier to obtain authorization information related to the display device from the current X authority file.

See the description of the SET DISPLAY command for more information.


/ALL (Alpha only)

Displays all named properties and their values related to the current display device.

/EXTRACT (Alpha only)

Obtains the authorization data for the display device and writes that data to SYS$OUTPUT. The authorization data is obtained from the current X authority file and is in the format expected by the X Authority utility (xauth).

Note that when using an LBX proxy server, the extracted authorization information references the address of the proxy server and not the X display server.

Do not use the /EXTRACT qualifier with any other SHOW DISPLAY qualifier.

See the description of the SET DISPLAY command for more information.

/QUOTA (Alpha only)

Displays the current name count and data space quota values for the display device. This display includes the set limit and the amount of space currently available for use.


Defines one or more global DCL symbols for each property displayed by the SHOW DISPLAY command. You can then use these property symbols in DCL command procedures.

Each global symbol name follows the form:


The following are the symbols for predefined properties:


Note that symbols for user-defined properties have a double underscore in the name. For example, the user-defined symbol for the value DISK$USER:[JONES] would be defined as follows:



If a symbol name or value exceeds or violates any DCL limits or naming conventions, the symbol is not set and an error message is displayed.

If the display device uses a proxy server, the symbols DECW$DISPLAY_NODE, DECW$DISPLAY_TRANSPORT, and DECW$DISPLAY_SERVER reflect values associated with the proxy server and not the X display server.

/VALUES=(property-name[,...]) (Alpha only)

Displays the value for the specified property. If the value consists of one or more items, they are displayed as a comma-delimited list.



  Device:     WSA1:  [super]
  Node:       0
  Transport:  LOCAL
  Server:     0
  Screen:     0

  Device:     WSA2:  [super]
  Node:       ZEPHYR
  Transport:  DECNET
  Server:     0
  Screen:     0


In this example, you are logged in to your workstation, here referred to as node 0. (0 is the standard shorthand notation for representing your node.) You want to run the DECwindows Clock on your workstation and display it on another node, ZEPHYR.

Assuming you are authorized to display applications on ZEPHYR, you redirect the application's output to ZEPHYR with the SET DISPLAY command and enter the SHOW DISPLAY command to verify the location of the redirected display. You then run Clock. Note that a new workstation display device, WSA2, is created when you enter the SET DISPLAY/CREATE command.


    Device:    WSA23:  [super]
    Node:      0
    Transport: DECNET
    Server:    0
    Screen:    0
  User-defined values:
    "DECW$SESSION_MANAGER" = "tcpip/zephyr:9510"
  DECW$DISPLAY__DECW$SESSION_MANAGER == "tcpip/zephyr:9510"


In this example, you create a display device, and set the DECW$SESSION_MANAGER property to the network address of a session manager on remote node ZEPHYR using port number 9510. The SHOW DISPLAY/SYMBOLS command then defines a DCL symbol for the port value.

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