Document revision date: 15 July 2002
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OpenVMS System Manager's Manual
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15.4.3 AUTOGEN Phases

When you invoke AUTOGEN, you specify a start phase and an end phase for AUTOGEN to execute. AUTOGEN executes all phases from the start phase to the end phase. Depending on the start phase and end phase you specify, AUTOGEN can execute any of the following phases, in the order shown in Table 15-2.

Table 15-2 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.

On VAX systems, the default parameter file is VAXVMSSYS.PAR. The original parameters are saved in the file VAXVMSSYS.OLD.

On Alpha systems, the default parameter file is ALPHAVMSSYS.PAR. The original parameters are saved in the file ALPHAVMSSYS.OLD.

SHUTDOWN Prepares the system to await a manual reboot.
REBOOT Automatically shuts down and reboots the system.
HELP Displays help information to the screen.

For detailed information about each AUTOGEN phase and the files affected by each phase, refer to the AUTOGEN section of the OpenVMS System Management Utilities Reference Manual.

15.4.4 AUTOGEN Parameter File (MODPARAMS.DAT)

AUTOGEN reads a parameter file named MODPARAMS.DAT during the GETDATA phase. You can add commands to this file to control the system parameter values and file sizes that AUTOGEN sets. You can use MODPARAMS.DAT to perform the following actions:
Operation For More Information
Increase the value of any numeric system parameter Section 15.5.1.1
Set a minimum value for a numeric system parameter Section 15.5.1.2
Set a maximum value for a numeric system parameter Section 15.5.1.3
Specify an absolute value for a system parameter Section 15.5.1.4
Include an external parameter file Section 15.5.3
Specify sizes of page, swap, and dump files Section 16.16.1.2
+Define the number of VAXcluster nodes Section 15.5.1.5
+Define the number of Ethernet adapters Section 15.5.1.6
+Preset parameter values before adding memory Section 15.5.1.7
Specify an alternate default startup command procedure Section 4.5.2

+VAX specific

To help track changes you make to MODPARAMS.DAT, make sure you add comments, preceded by the exclamation point (!), each time you change the file.

Caution
The recommended method of changing system parameters and system file sizes is to edit MODPARAMS.DAT to include parameter settings. If you change a system parameter value or file size using SYSMAN, SYSGEN, or a conversational boot, and you do not specify the value in MODPARAMS.DAT, AUTOGEN will recalculate the value or file size the next time it runs. For more information, see Section 15.5.1.

Example

The following example shows the contents of a sample MODPARAMS.DAT file: 


! 
! ***************** A Sample MODPARAMS.DAT for Node NODE22 *************** 
! 
! MODPARAMS.DAT for "NODE22" 
! REVISED: 04/29/00 -CHG- Upped GBLPAGES to account for ADA. 
! 
SCSNODE         = "NODE22"      ! This is not calculated by AUTOGEN. 
SCSSYSTEMID     = 19577         ! This is not calculated by AUTOGEN. 
TTY_DEFCHAR2    = %X0D34        ! This is not calculated by AUTOGEN. 
ADD_ACP_DIRCACHE= 150           ! Hit rate was only 65% on directory cache. 
MIN_PAGEDYN     = 500000        ! PAGEDYN must be at least 1/2 Mbyte to 
                                ! account for a large number of logical names. 
! 
 
MAX_PAGEFILE1_SIZE  = 15000     ! Maximum size for primary page. 
MAX_SWAPFILE        =  5000     ! Maximum size for swap file space. 
MAX_DUMPFILE        = 32768     ! Maximum size for dump file space. 
 
ADD_GBLPAGES    = 425+507+157   ! Account for MCS, BLISS32 and ADA. 
ADD_GBLSECTIONS = 4 + 5 + 2     ! Account for MCS, BLISS32 and ADA. 
VIRTUALPAGECNT  = 144264        ! So that we can read MONSTR's 68Mb dumps. 
! 
! end of MODPARAMS.DAT for NODE22

15.5 Modifying System Parameters with AUTOGEN

The recommended method of modifying system parameters is to execute AUTOGEN in two passes, as follows:

  1. First pass---Execute AUTOGEN using the following command: 


    $ @SYS$UPDATE:AUTOGEN SAVPARAMS TESTFILES

    This command instructs AUTOGEN to perform the following actions:

    Review the input to the calculations (PARAMS.DAT), the output from the calculations (SETPARAMS.DAT), and the report generated (AGEN$PARAMS.REPORT).
    If you are not satisfied with the parameter settings, modify the parameter values by editing MODPARAMS.DAT as explained in Section 15.5.1. If you are not satisfied with the file sizes, modify the sizes as explained in Section 16.16. Then reexecute AUTOGEN from the GETDATA phase.
    When you are satisfied with the contents of SETPARAMS.DAT, go to step 2.
  2. Second pass---Execute AUTOGEN a second time using the following command: 


    $ @SYS$UPDATE:AUTOGEN GENPARAMS REBOOT

    This AUTOGEN command runs SYSMAN to update the new system parameter values and installs them on the system when it is rebooted.

15.5.1 Controlling AUTOGEN's Parameter Settings with MODPARAMS.DAT

If, after examining the AGEN$PARAMS.REPORT or SETPARAMS.DAT file, you decide to correct hardware configuration data or modify system parameter values chosen by AUTOGEN, edit the MODPARAMS.DAT file as described in this section to manually specify parameter values.

Caution
Always edit MODPARAMS.DAT to specify values for parameters. Do not edit PARAMS.DAT; modifying the contents of this file might prevent AUTOGEN from operating correctly.

For information about editing MODPARAMS.DAT to control sizes of page, swap, and dump files, see Section 16.16.1.2.

You can define symbols in MODPARAMS.DAT using the following formats to control parameter values:
Control Method Symbol Format For More Information
Increase a value by a specified amount ADD_* Section 15.5.1.1
Specify a minimum value MIN_* Section 15.5.1.2
Specify a maximum value MAX_* Section 15.5.1.3
Specify an absolute value Parameter name Section 15.5.1.4

When defining symbols in MODPARAMS.DAT, make sure to adhere to the following criteria:

Caution
When AUTOGEN reads MODPARAMS.DAT or any other parameter file, it checks to determine if the symbol names specified in the file are valid. If they are not, AUTOGEN writes a warning message to AGEN$PARAMS.REPORT. However, AUTOGEN checks only the symbol name; it does not check the validity of the value specified for the symbol.

If a value is invalid, the line is not ignored. AUTOGEN attempts to use the specified value.

A symbol is not checked if it is specified in a line that contains a DCL expression other than the equal sign (=). For example, AUTOGEN does not check the validity of a symbol name specified in a line with the DCL IF statement. Instead, AUTOGEN writes a warning message to AGEN$PARAMS.REPORT.

To help track changes you make to MODPARAMS.DAT, make sure you add comments preceded by an exclamation point (!) each time you change the file.

15.5.1.1 Increasing a Value with the ADD_ Prefix

Use the ADD_ prefix to increase the value of any numeric parameter. The new values are updated in subsequent AUTOGEN calculations during the GENPARAMS phase. The following example demonstrates the use of the ADD_ prefix: 


ADD_GBLPAGES=500 
ADD_NPAGEDYN=10000
An ADD_ parameter record for a parameter that AUTOGEN calculates will add the value to AUTOGEN's calculations. An ADD_ parameter record for a parameter that AUTOGEN does not calculate will add the value to the parameter's default (not current) value. (Refer to the AUTOGEN section on the OpenVMS System Management Utilities Reference Manual for a table of parameters affected by AUTOGEN.)

Note
The ADD_ value is added to the calculated value once, and does not accumulate with successive runs for feedback calculations.

Typically, you would not use the ADD_ prefix for modifying parameters that are calculated by the feedback mechanism, because the feedback results should accurately reflect your work load. However, if you do use the ADD_ prefix with feedback, AUTOGEN adds a value only once if AUTOGEN is run to the SETPARAMS phase or beyond. To maintain a minimum level above AUTOGEN's calculation, use the MIN_ prefix.

15.5.1.2 Specifying a Minimum Value with the MIN_ Prefix

Use the MIN_ prefix if you do not want AUTOGEN to set a parameter below a specified value. MIN_ refers to the minimum value to which a parameter can be set by AUTOGEN. The following example sets the minimum value to 400,000: 


MIN_PAGEDYN = 400000

15.5.1.3 Specifying a Maximum Value with the MAX_ Prefix

Use the MAX_ prefix if you do not want AUTOGEN to set a parameter above a specified value. MAX_ refers to the maximum value to which a parameter can be set by AUTOGEN. The following example sets the maximum value to 400,000: 


MAX_PAGEDYN = 400000

15.5.1.4 Specifying an Absolute Value

Use this method to specify a value for a parameter that AUTOGEN does not calculate. (Refer to the AUTOGEN section of the OpenVMS System Management Utilities Reference Manual for a table of the system parameters modified in AUTOGEN calculations.)

Note
Compaq strongly recommends that you use this method only for parameters that describe the system environment (for example, SCSNODE and SCSSYSTEMID). For the parameters that AUTOGEN calculates, specifying a value with this method disables AUTOGEN's calculations. Instead of specifying an absolute value, use one of the following methods:
  • Specify a minimum value with the MIN_ prefix
  • Specify a maximum value with the MAX_ prefix
  • Increase the value with the ADD_ prefix

To specify an absolute parameter value, add an assignment statement in the following format to MODPARAMS.DAT:

parameter = parameter-value ! comment

For example, the following command assigns the node name BIGVAX to the SCSNODE parameter: 


SCSNODE = "BIGVAX"   ! the node name

Note
String values must be within quotation marks ("").

15.5.1.5 Defining the Number of VAXcluster Nodes (VAX Only)

In a VAXcluster environment, use the NUM_NODES symbol to prevent temporary changes in VAXcluster membership from affecting AUTOGEN's calculation of VAXcluster-related parameter values. Define the NUM_NODES symbol in MODPARAMS.DAT to specify the number of nodes that are to run in the VAXcluster. AUTOGEN uses this value to set parameters that are affected by the number of VAXcluster nodes. For example, include the following line in MODPARAMS.DAT: 


NUM_NODES = 30

15.5.1.6 Defining the Number of Ethernet Adapters (VAX Only)

In a VAXcluster environment, define the NUM_ETHERADAPT symbol in MODPARAMS.DAT to specify the total number of Ethernet adapters in the VAXcluster system. For example, include the following line in MODPARAMS.DAT: 


NUM_ETHERADAPT = 40

15.5.1.7 Presetting Parameter Values Before Adding Memory (VAX Only)

On VAX systems, if you plan to upgrade your system hardware by adding a large amount (512 MB or more) of memory, you might want to preset your system parameters to values appropriate for the additional memory. Presetting your system parameters minimizes the possibility of memory upgrade problems caused by inappropriate parameter values.

How to Perform This Task

Perform the following steps:

  1. Add a line to SYS$SYSTEM:MODPARAMS.DAT in the following format:

    MEMSIZE = total-number-of-pages-of-memory-after-upgrade


    For example: 


    MEMSIZE = 2048 * 1024 ! (2048 page per MB *  1GB of memory)

  2. Run AUTOGEN to the SETPARAMS phase.
  3. Perform the hardware upgrade to add the additional memory.
  4. Edit MODPARAMS.DAT to remove the line added in step 1.

15.5.1.8 Overriding Parameters Related to DECnet

To override AUTOGEN's observations regarding the presence (or absence) of DECnet, set the MODPARAMS.DAT parameter LOAD_DECNET_IMAGES to TRUE (or FALSE). Controlling the setting is useful for sites that have no synchronous network hardware but want to run asynchronous DECnet.

15.5.1.9 Values Set for NPAGEDYN and NPAGEVIR

For the benefit of OpenVMS VAX systems with limited physical memory, AUTOGEN logs a warning message in its report if NPAGEDYN exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33 percent of physical memory.

AUTOGEN also limits its own calculated value for NPAGEDYN to 20 percent of physical memory, and limits NPAGEVIR to 50 percent of physical memory. These calculated values are adequate for most workstations and systems with 16 or fewer megabytes of physical memory. If your system requires a larger value, you can override the AUTOGEN calculated values by setting higher values in MODPARAMS.DAT.

15.5.2 Specifying a Minimum Required Age for Feedback (VAX Only)

On VAX systems, AUTOGEN feedback is useful only when a system has been running long enough to accurately reflect the system's normal work load. By default, AUTOGEN uses feedback if the data is older than 24 hours. On VAX systems, you can define the logical name AGEN$FEEDBACK_REQ_TIME to specify, in hours, a different minimum age required for feedback. AUTOGEN uses this value to determine whether the feedback is to be used.

For example, you might define the logical name as follows, to indicate that AUTOGEN should use feedback if it is older than 19 hours: 


$
DEFINE/SYSTEM AGEN$FEEDBACK_REQ_TIME 19

To define this logical name each time the system starts up, add this command to SYLOGICALS.COM.

15.5.3 Including an External Parameter File in MODPARAMS.DAT

You can include external parameter files in MODPARAMS.DAT. For example, you might want to set a system parameter to the same value on all nodes in a VAXcluster or an OpenVMS Cluster environment; you might also want to specify node-specific values for other system parameters. You could specify the cluster-common values in a separate cluster-common file and include this cluster-common file in the MODPARAMS.DAT file on each system in the cluster.

To include a parameter file, place a command in the following format in MODPARAMS.DAT, or in any parameter file that is included in MODPARAMS.DAT:

AGEN$INCLUDE_PARAMS full-directory-spec:filename

Example

To include a cluster-common parameter file named CLUSTERPARAMS.DAT, create a common parameter file with the following name:

SYS$COMMON:[SYSEXE]CLUSTERPARAMS.DAT

Add the following line in the MODPARAMS.DAT file in the system-specific directory of each cluster: 


AGEN$INCLUDE_PARAMS SYS$COMMON:[SYSEXE]CLUSTERPARAMS.DAT

15.5.4 Turning Off Logging of DCL Statements

The contents of MODPARAMS.DAT are evaluated as DCL statements; you can make assignments to symbols with names that are not system parameters (for example, scratch variables or conditional assignments based on other values). Traditionally, every such assignment is logged in AGEN$PARAMS.REPORT, sometimes creating a large file with many logging statements that do not interest users.

You can prefix any assignments that you prefer not to log in AGEN$PARAMS.REPORT with a dollar sign ($). When AUTOGEN encounters a MODPARAMS.DAT record beginning with a dollar sign, it does not check the list of known system parameters and does not log this record to AGEN$PARAMS.REPORT.

15.6 Automating AUTOGEN Reports

Compaq recommends that you create a batch-oriented command procedure to automatically run AUTOGEN on a regular basis and send the resulting feedback reports to an appropriate Mail account. Example 15-2 provides a sample command procedure.

Note
This command procedure runs AUTOGEN only to recommend system parameter values and send you a report. It does not run AUTOGEN to change system parameters or reboot the system. If, after reviewing the report, you decide to change system parameters, follow the instructions in Section 15.6.1.

The command procedure in Example 15-2 runs two passes of AUTOGEN. On the first pass, AUTOGEN runs during peak workload times to collect data on realistic system work loads. This pass does not degrade system performance. On the second pass, AUTOGEN runs during off-peak hours to interpret the data collected in the first stage.

The procedure sends the resulting report, contained in the file AGEN$PARAMS.REPORT, to the SYSTEM account. Review this report on a regular basis to see whether the load on the system has changed.

Example 15-2 shows a sample command procedure. Use this procedure only as an example; create a similar command procedure as necessary to meet the needs of your configuration.

Example 15-2 Sample AUTOGEN Command Procedure 

$ BEGIN$:   ! ++++++++++ AGEN_BATCH.COM ++++++++++ 
$  on warning then goto error$ 
$  on control_y then goto error$ 
$! 
$! Setup process 
$! 
$! Set process information 
$  set process/priv=all/name="AUTOGEN Batch" 
$! Keep log files to a reasonable amount 
$  purge/keep=5 AGEN_Batch.log 
$  time = f$time()    ! Fetch current time 
$  hour = f$integer(f$cvtime(time,,"hour")) ! Get hour 
$  today = f$cvtime(time,,"WEEKDAY")  ! Get Day of the week 
$  if f$integer(f$cvtime(time,,"minute")) .ge. 30 then hour = hour + 1 
$! 
$! Start of working day... 
$! 
$ 1AM$:                                      
$  if hour .le. 2 
$     then 
$     next_time = "today+0-14" 
$     gosub submit$    ! Resubmit yourself 
$     set noon 
$! 
 
$!      Run AUTOGEN to TESTFILES using the parameter values collected earlier 
 
$!      in the day (i.e., yesterday at 2:00pm) 
$       if today .eqs. "Tuesday" .OR. today .eqs. "Thursday" .OR. - 
    today .eqs. "Saturday" 
$          then 
$      @sys$update:autogen GETDATA TESTFILES feedback (2)
$      mail/sub="AUTOGEN Feedback Report for system-name" - 
  sys$system:agen$params.report system (3)
$      ! Clean up 
$            purge/keep=7 sys$system:agen$feedback.report (4)
$            purge/keep=7 sys$system:agen$feedback.dat 
$            purge/keep=7 sys$system:params.dat 
$            purge/keep=7 sys$system:autogen.par 
$            purge/keep=7 sys$system:setparams.dat 
$            purge/keep=7 sys$system:agen$addhistory.tmp 
$            purge/keep=7 sys$system:agen$addhistory.dat 
$        endif 
$     goto end$ 
$     endif 
$! 
$ 2PM$: 
$  if hour .le. 15 
$     then 
$     next_time = "today+0-17" 
$     gosub submit$ 
$     if today .eqs. "Monday" .OR. today .eqs. "Wednesday" .OR. - 
  today .eqs. "Friday" 
$        then 
$          @sys$update:autogen SAVPARAMS SAVPARAMS feedback (1)
$        endif 
$     goto end$ 
$     endif 
$! 
$ 5PM$: 
$  if hour .le. 18 
$     then 
$     next_time = "tomorrow+0-1" 
$     gosub submit$ 
$     endif 
$! 
$! End of working day... 
$! 
$ END$:     ! ---------- BATCH.COM ---------- 
$  exit 
$!++ 
$! Subroutines 
$!-- 
$! 
$ SUBMIT$: 
$  submit/name="AGEN_Batch"/restart/noprint - (5)
   /log=AGEN_batch.log - 
   /queue=sys$batch/after="''next_time'" sys$system:AGEN_batch.com 
$  return 
$!++ 
$! Error handler 
$!-- 
$ ERROR$: 
$  mail/sub="AGEN_BATCH.COM - Procedure failed." _nl: system 
$  goto end$

The commands in this procedure perform the following tasks:

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