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HP OpenVMS System Management Utilities Reference Manual

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Chapter 6
AUTOGEN Command Procedure

6.1 AUTOGEN Description

The AUTOGEN command procedure (SYS$UPDATE:AUTOGEN.COM) sets appropriate values for system parameters and sizes for system page, swap, and dump files. AUTOGEN runs automatically when you install or upgrade the operating system.

In addition, you can use AUTOGEN to reset system parameter values, system file sizes, or both. The new values and file sizes take effect the next time the system is booted.

HP recommends that you run AUTOGEN on a weekly basis to adjust system parameters according to your system's work load. For a list and description of all system parameters, see Appendix K

AUTOGEN executes in phases, with each phase performing a separate task. You control which tasks AUTOGEN performs by specifying a start phase and an end phase when you invoke AUTOGEN. For more information about the AUTOGEN phases, see Section 6.4.

You can add commands to the file SYS$SYSTEM:MODPARAMS.DAT to control the system parameter values and file sizes that AUTOGEN sets. AUTOGEN uses the information in this file to determine final values for system parameters or page, swap or dump file sizes. For more information, see the chapter about managing system parameters in the HP OpenVMS System Manager's Manual.

AUTOGEN can improve system performance by using dynamic information, called feedback, which is gathered from the running system.


When making major configuration changes, do not use feedback. Specify nofeedback to assure the use of the initial AUTOGEN settings. See Table 6-2 for more information about nofeedback.
You control how AUTOGEN uses feedback by specifying an execution mode when you invoke AUTOGEN. To direct AUTOGEN to use feedback to make its calculations, run AUTOGEN in feedback mode. After a period of time, you can execute AUTOGEN in feedback mode to further refine system parameter settings. For more information about AUTOGEN feedback, see Section 6.3.


The following sections explain how AUTOGEN uses NEWPARAMS.DAT and how layered product installation procedures can use it. If you are not involved in making layered product kits, you might not be interested in the sections preceding Section

The basic reason for developing NEWPARAMS.DAT has been to provide a way for layered product installation procedures to easily supply AUTOGEN with the necessary parameter changes for the product. NEWPARAMS.DAT greatly reduces (if not eliminates) the need to modify MODPARAMS.DAT after installing a new layered product and avoids having installation procedures attempt to edit MODPARAMS.DAT.

NEWPARAMS.DAT does not replace or make MODPARAMS.DAT obsolete, and it does not remove the requirement to run AUTOGEN after installing a layered product. (AUTOGEN can, however, process several versions of NEWPARAMS.DAT, which you might have if you install several layered products without running AUTOGEN between installations). How NEWPARAMS.DAT Works

Three files are involved in the operation of NEWPARAMS.DAT:

    This file contains the parameter requirements for a particular layered product.
    AUTOGEN renames each NEWPARAMS.DAT to NEWPARAMS.DONE as soon as it has finished processing the file.


    If AUTOGEN finds three versions of NEWPARAMS.DAT, it processes version 3, then version 2, and then version 1. After AUTOGEN has renamed the files to NEWPARAMS.DONE, their version numbers ARE reversed, reflecting the fact that the oldest file was processed and renamed the most recently.
    The system manager can purge these files at any time. AUTOGEN, however, does not delete these files immediately so that you can examine them if some problem occurs with the layered product installation or with a subsequent run of AUTOGEN.
    This file receives the parameter values of the NEWPARAMS.DAT files that AUTOGEN processes.

In NEWPARAMS.DAT the AUTOGEN code expects to find records that are comments (which are not passed to CLU$PARAMS.DAT), and parameter assignments very much like those in MODPARAMS.DAT. These are usually assignments similar to ADD_parameter and MIN_parameter:

  • The first setting, ADD_parameter, defines the amount of a particular resource (for example, NPAGEDYN, GBLPAGES) the layered product requires.
  • The second setting, MIN_parameter, provides floor for the calculation of a parameter (for example, PQL_DWSDEFAULT).

The parameter settings in NEWPARAMS.DAT are integrated into CLU$PARAMS.DAT. This file is then used, along with MODPARAMS.DAT and the feedback and hardware configuration data, to calculate parameter values in the GENPARAMS phase. System managers do not need to modify CLU$PARAMS.DAT; MODPARAMS.DAT continues to be the proper file to contain system-specific parameter changes. What Goes into NEWPARAMS.DAT

The following sections describe what is placed in the NEWPARAMS.DAT file. Product Name

A very important difference between the parameter assignments in MODPARAMS.DAT, which is familiar to most system managers, and those in NEWPARAMS.DAT: the name of the layered product that makes the assignments.


If the name of the product changes from one kit to the next, the system ends up with parameter changes made under both names. Therefore, choose the name carefully so that you do not need to change it in future kits. In addition, do not include version numbers.

AUTOGEN no longer allows layered product kits to provide NEWPARAMS.DAT records that do not include a product name.

You can pass the layered product name to AUTOGEN in either of the following ways:

  • Prepend the name and a dollar-sign ($) to each parameter name; for example:

  • Include the name as a comment, which must begin as follows:

        !Set by   

    The entire remainder of the comment is used as the product name for example:

        MIN_GBLPAGES=62000         !Set by DW-MOTIF 

    In this example, DW-MOTIF becomes the product name.

The first method takes precedence over the second method. For example, someone might enter a value like the following:

 ABBOTT$add_npagedyn=1000000 !Set by COSTELLO 

In this example, the prefix (ABBOTT) will be used, and the product name specified in the comment (COSTELLO) will be ignored.

HP recommends that you use one method or the other to avoid confusion. Parameter Assignment

Except for specifying the product name, parameter assignment with NEWPARAMS.DAT works the same as it does in MODPARAMS.DAT, where you can set values, floors and ceilings, and specify amounts to add to a parameter; for example:

        WINDOW_SYSTEM = 1 
        MIN_GBLSECTIONS = 600 
        MAX_WSMAX = 250000 
        ADD_GBLPAGES = 25000 How to Remove Assignments from CLU$PARAMS.DAT

You might want to remove one or more parameter assignments from CLU$PARAMS.DAT for a number of reasons. A layered product might no longer need to use a value other than the default value of a parameter. Also, occasionally OpenVMS Engineering makes a parameters obsolete (for example, VIRTUALPAGECNT), and layered product kits need to include a way to remove these parameters from a system.

To remove an assignment from CLU$PARAMS.DAT, create a NEWPARAMS.DAT that includes either of the following syntaxes:

   AGEN$REMOVE_PARAM  <parameter>  !Set by <product> 
   AGEN$REMOVE_PARAM  <product>$<parameter> 

The rules explained in Section for specifying product names also apply here. Also, you can mix such removals with assignments in a single NEWPARAMS.DAT file. Use removals to remove assignments of parameters that will no longer be needed; to change a parameter value, simply assign the new value to the parameter in NEWPARAMS.DAT, and the new value will replace the old value.

Note that AUTOGEN does not parse anything between the parameter name and the !Set by comment. This allows the kit producer to use NEWPARAMS.DAT for installation and to create a NEWPARAMS.DAT for deinstallation by prepending "AGEN$REMOVE_PARAM " to the beginning of each line. What CLU$PARAMS.DAT Looks Like

The format of CLU$PARAMS.DAT, which is used to define layered- product-driven parameter modifications, is as follows:

!   The file contains parameters supplied by layered products. 
!  It should not be modified.  Customer parameters should be placed in 
DW_MOTIF$MIN_CHANNELCNT = 255                     !Set by DW-MOTIF 
DW_MOTIF$ADD_GBLPAGES = 28000                     !Set by DW-MOTIF 
DW_MOTIF$MIN_GBLPAGES = 62000                     !Set by DW-MOTIF 
DW_MOTIF$ADD_GBLPAGFIL = 5000                     !Set by DW-MOTIF 
DW_MOTIF$MIN_GBLPAGFIL = 6024                     !Set by DW-MOTIF 
DECNET_PLUS$MIN_GBLPAGES = 55000                  !Set by DECnet-Plus 
DECNET_PLUS$ADD_GBLPAGES = 24000                  !Set by DECnet-Plus 

This example shows two layered product installations that use NEWPARAMS.DAT: one is DW-MOTIF (the DECWindows kit), and the other is DECnet-Plus.

A subsequent installation of DW-MOTIF replaces the value of each parameter assignment in CLU$PARAMS.DAT with the value found in NEWPARAMS.DAT. Whether the new kit has 255, 200 or 300 for MIN_CHANNELCNT, the value that is supplied is the value found in the new copy of CLU$PARAMS.DAT.

Similarly, the new value that DW_MOTIF provides for ADD_GBLPAGES replaces the 28000 in the assignment of ADD_GBLPAGES shown in the last example. These values are not cumulative for a given product; they do, however, accumulate across layered products; therefore, the total ADD_GBLPAGES value are as follows:

 28000 + 24000, or 52000 

Both NEWPARAMS.DAT and CLU$PARAMS.DAT are ordinary text files created by text editors. HP does not recommend editing these files.

6.2 AUTOGEN Usage Summary

HP recommends that you run AUTOGEN in the following circumstances:

  • During a new installation or upgrade.
  • Whenever your work load changes significantly.
  • When you add an optional (layered) software product. Certain layered products might require you to execute AUTOGEN to adjust parameter values and page and swap file sizes. (For information about using AUTOGEN to modify page and swap files, see the chapter on managing page, swap, and dump files in the HP OpenVMS System Manager's Manual.) For installation requirements, see specific product documentation.
  • When you install images with the /SHARED attribute. The GBLSECTIONS and GBLPAGES parameters might need to be increased to accommodate additional use of global pages and global sections.
  • During normal operation, as part of a batch-oriented command procedure that runs AUTOGEN on a regular basis and automatically sends a report to an appropriate Mail account. The recommended procedure is described in the chapter on managing system parameters in the HP OpenVMS System Manager's Manual.

After a new operating system installation or upgrade, examine the results of calculations that AUTOGEN made to determine whether AUTOGEN has set system parameter values that are appropriate for your workload requirements.

The system parameters listed in an appendix to this manual indicate whether they are affected by AUTOGEN calculations. AUTOGEN calculations also affect the size of page, swap and dump files.

6.3 Feedback

AUTOGEN feedback minimizes the necessity to modify parameter values or system file sizes. Feedback allows AUTOGEN to automatically size the operating system based on your actual work load. Sizing is the process of matching the allocation of system resources (memory and disk space) with the workload requirements of your site.

Feedback is information about how various resources are used by the system's work load. This information is continuously collected by the operating system executive. Because the system collects feedback when exception events occur, feedback collection does not affect system performance.

You control how AUTOGEN uses feedback by specifying an execution mode when you invoke AUTOGEN. When run in feedback mode, AUTOGEN analyzes this information and adjusts any related parameter values. For information about controlling AUTOGEN's use of feedback, see Section 6.5.

AUTOGEN collects feedback during the SAVPARAMS phase by executing the image SYS$SYSTEM:AGEN$FEEDBACK.EXE. AUTOGEN writes feedback information to the file SYS$SYSTEM:AGEN$FEEDBACK.DAT. This file is then read during the GETDATA phase. For more information about AUTOGEN phases, see Section 6.4.

The system parameters listed in an appendix to this manual indicate whether they are affected by AUTOGEN feedback.

6.4 Phases

AUTOGEN executes in phases. You control which tasks AUTOGEN performs by specifying a start phase and an end phase when you invoke AUTOGEN. Table 6-1 lists the phases AUTOGEN can execute in order.

Table 6-1 AUTOGEN Phases
Phase Description
SAVPARAMS Saves dynamic feedback from the running system.
GETDATA Collects all data to be used in AUTOGEN calculations.
GENPARAMS Generates new system parameters; creates the installed image list.
TESTFILES Displays the system page, swap, and dump file sizes calculated by AUTOGEN (cannot be used as a start phase).
GENFILES Generates new system page, swap, and dump files if appropriate (cannot be used as a start phase).
SETPARAMS Runs SYSMAN to set the new system parameters in the default parameter file, saves the original parameters, and generates a new parameter file, AUTOGEN.PAR.
SHUTDOWN Prepares the system to await a manual reboot.
REBOOT Automatically shuts down and reboots the system.
HELP Displays help information to the screen.

The following sections describe each phase in detail.


The SAVPARAMS phase records feedback in the file AGEN$FEEDBACK.DAT, which can be used in subsequent AUTOGEN phases. If you specify NOFEEDBACK as the execution-mode parameter, the information collected is not used.

The SAVPARAMS phase is valid as a start phase and end phase. SAVPARAMS requires the SYSPRV and CMKRNL privileges.


You can specify the SAVE_FEEDBACK option during an interactive orderly shutdown with SYS$SYSTEM:SHUTDOWN.COM. Entering this option in response to the prompt "Shutdown options:" records feedback collected since the system was last booted. Using the SAVE_FEEDBACK option creates a new version of SYS$SYSTEM:AGEN$FEEDBACK.DAT. Run AUTOGEN from the GETDATA phase after the system reboots to use this new version of the feedback.


The GETDATA phase collects the following information required for AUTOGEN calculations and places it in the file PARAMS.DAT:

  • Hardware configuration data
  • HP-supplied data from CLU$PARAMS.DAT
  • Feedback from AGEN$FEEDBACK.DAT (if run in feedback mode)
  • User-supplied data from MODPARAMS.DAT

The GETDATA phase also attempts to configure devices on the system, by executing the following procedure and command:

  • The command procedure SYS$MANAGER:SYCONFIG.COM. (For more information about this procedure, see the chapter on managing devices in the HP OpenVMS System Manager's Manual.)
  • The SYSGEN command AUTOCONFIGURE ALL (unless the symbol STARTUP$AUTOCONFIGURE_ALL is set to 0 in SYCONFIG.COM).

The GETDATA phase is valid as a start phase and an end phase. GETDATA requires the SYSPRV and CMKRNL privileges.


In the GENPARAMS phase, AUTOGEN calculates the parameter values based on data stored in PARAMS.DAT and produces SETPARAMS.DAT as output. AUTOGEN checks to see if feedback is included, and if so, uses it in the calculations unless the NOFEEDBACK execution mode was specified when AUTOGEN was invoked. Also during this phase, AUTOGEN generates the known image file list (VMSIMAGES.DAT).

The GENPARAMS phase is valid as a start phase and an end phase. GENPARAMS requires SYSPRV, OPER, and CMKRNL privileges.


The TESTFILES phase displays system page, swap, and dump file sizes calculated by AUTOGEN. (This phase does not change the file sizes.)

File sizes for all currently installed primary and secondary page and swap files are displayed. The information is directed to SYS$OUTPUT and the AGEN$PARAMS.REPORT file by default.

Specify the TESTFILES phase to display AUTOGEN's file size calculations; to generate new sized files, specify the GENFILES phase. You cannot specify both of these phases when invoking AUTOGEN. HP recommends that you use TESTFILES to display the file size changes before actually generating new sized files on your system.

The TESTFILES phase is valid only as an end phase. TESTFILES requires the SYSPRV privilege.


The GENFILES phase generates the new page, swap, and dump files on the system. This phase changes the file sizes based on AUTOGEN's calculations.

The GENFILES phase does not modify a file if the calculated size change is within ten percent of the existing file size. The following files are affected: PAGEFILE.SYS, SWAPFILE.SYS, SYSDUMP.DMP, and all other currently installed page and swap files. For more information, see the chapter on managing page, swap and dump files in the HP OpenVMS System Manager's Manual.

GENFILES is valid only as an end phase. GENFILES requires the SYSPRV privilege.


The SETPARAMS phase uses as its input the SETPARAMS.DAT file created during the GENPARAMS phase. In this phase, AUTOGEN runs SYSMAN to update the system parameter values in the default parameter file.

On Alpha systems, SYS$SYSTEM:ALPHAVMSSYS.PAR is the default parameter file. AUTOGEN saves the current system parameters in the file SYS$SYSTEM:ALPHAVMSSYS.OLD before updating these parameters in SYS$SYSTEM:ALPHAVMSSYS.PAR. The new values are also saved in SYS$SYSTEM:AUTOGEN.PAR.

On Integrity servers, SYS$SYSTEM:IA64VMSSYS.PAR is the default parameter file. AUTOGEN saves the current system parameters in the file SYS$SYSTEM:IA64VMSSYS.OLD before updating these parameters in SYS$SYSTEM:IA64VMSSYS.PAR. The new values are also saved in SYS$SYSTEM:AUTOGEN.PAR.

The SETPARAMS phase is valid as a start phase and an end phase. SETPARAMS requires the SYSPRV and OPER privileges.

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