Converting Your Customized Parameter Settings for Use with AUTOGEN

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HP OpenVMS System Manager's Manual, Volume 2:...

Managing System Parameters

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Understanding the AUTOGEN Command Procedure

Converting Your Customized Parameter Settings for Use with AUTOGEN

HP recommends that you use the AUTOGEN command procedure to tune your system. If you use the System Management utility (SYSMAN) or the System Generation utility (SYSGEN) to modify system parameter values, and you do not include these changes in the AUTOGEN parameter file MODPARAMS.DAT, these changes will be overridden the next time you run AUTOGEN.

If you used SYSMAN or SYSGEN to change parameter values in the past, use the following procedure to convert your parameter settings to work with AUTOGEN. This procedure explains how to add your customized parameter settings to MODPARAMS.DAT so they will be retained when you run AUTOGEN.

Before performing this task, you should understand AUTOGEN, feedback, and the AUTOGEN parameter file MODPARAMS.DAT, as explained in Understanding the AUTOGEN Command Procedure.

Save the parameter values that the system is now using as follows:

$ RUN SYS$SYSTEM:SYSMAN
SYSMAN> PARAMETERS USE ACTIVE
SYSMAN> PARAMETERS WRITE SYS$SYSTEM:nodename_PARAMS_CURRENT.PAR

Write a listing of the active parameter values to an ASCII file named nodename_PARAMS.OLD as follows:

SYSMAN> PARAMETERS SHOW/ALL/OUTPUT=nodename_PARAMS.OLD
SYSMAN> PARAMETERS SHOW/SPECIAL/OUTPUT=nodename_PARAMS_SPECIAL.OLD
SYSMAN> EXIT
$ APPEND nodename_PARAMS_SPECIAL.OLD nodename_PARAMS.OLD

You will use this file in step 6.

Edit AUTOGEN's parameter file SYS$SYSTEM:MODPARAMS.DAT to define symbols to specify values for the following parameters:
- Parameter values that are not calculated by AUTOGEN, such as SCSNODE and SCSSYSTEMID. Refer to the AUTOGEN description in the HP OpenVMS System Management Utilities Reference Manual for a table of the parameters calculated by AUTOGEN.
- Any parameter values that must be adjusted to suit your system work load, for example, GBLPAGES and GBLSECTIONS.
To specify a value, define symbols using the format MIN_parameter, MAX_parameter, or ADD_parameter rather than specifying an explicit value. For example:
```
$ EDIT SYS$SYSTEM:MODPARAMS.DAT
```
```
SCSNODE = "MYNODE" 	! Not calculated by AUTOGEN
SCSSYSTEMID = 10001 	! Not calculated by AUTOGEN
MIN_GBLPAGES = 10000 	! Needed for MCS, BLISS32, and ADA
MIN_GBLSECTIONS = 600 	! Needed for MCS, BLISS32, and ADA
```
To help you track the changes you make in MODPARAMS.DAT, add comments to each line, preceded by an exclamation point (!). For information about defining symbols in MODPARAMS.DAT, see Controlling AUTOGEN's Parameter Settings with MODPARAMS.DAT.

Run AUTOGEN, but do not reboot. Use one of the following commands, depending on your system:
- If the system has run a typical work load for more than 24 hours since last booting:
```
$ @SYS$UPDATE:AUTOGEN SAVPARAMS SETPARAMS FEEDBACK
```
  The SAVPARAMS phase collects feedback information about resource use on the running system; this information is used by AUTOGEN. This command creates a feedback report named SYS$SYSTEM:AGEN$PARAMS.REPORT, which tells you about peak resource use.
- If you want to use a previously collected feedback file:
```
$ @SYS$UPDATE:AUTOGEN GETDATA SETPARAMS FEEDBACK
```
  If you start from the GETDATA phase, AUTOGEN does not collect current feedback.
- If this is a new system (that is, it has no feedback) or the system has had little activity since last boot (for example, over the weekend) so there is no valid feedback file:
```
$@SYS$UPDATE:AUTOGEN GETDATA SETPARAMS CHECK_FEEDBACK
```
  Use the CHECK_FEEDBACK parameter to let AUTOGEN determine whether the feedback is valid.

Write a listing of the new parameter values to an ASCII file as follows:

$ RUN SYS$SYSTEM:SYSMAN
SYSMAN> PARAMETERS USE CURRENT
SYSMAN> PARAMETERS SHOW /ALL /OUTPUT=nodename_PARAMS.NEW
SYSMAN> PARAMETERS SHOW /SPECIAL /OUTPUT=nodename_PARAMS_SPECIAL.NEW
SYSMAN> EXIT
$ APPEND nodename_PARAMS_SPECIAL.NEW nodename_PARAMS.NEW

Compare the old and new parameter values as follows:

$ DIFFERENCES/PARALLEL/OUTPUT=nodename_PARAMS.DIF/MATCH=5  -
_$ nodename_PARAMS.OLD nodename_PARAMS.NEW

Print the differences file you created in step 6 (named in the format nodename_PARAMS.DIF). Print the file on a 132-column line printer to make the output easier to read.

Compare the numbers in the two columns following each parameter name column. The left column shows the old value; the right column shows the new value. Old and New Parameter Values illustrates sample output.

Figure 1 Old and New Parameter Values

Make any adjustments in MODPARAMS.DAT using symbols prefixed by MIN_, MAX_, or ADD_. For example, if AUTOGEN calculated a smaller value for GBLPAGES, you might specify a minimum value for this parameter as follows:
```
MIN_GBLPAGES = 10000
```
If you originally specified a parameter value in MODPARAMS.DAT (in step 3) but the parameter has not been changed, verify the following data:
- The parameter name is spelled correctly and completely (not abbreviated). In MODPARAMS.DAT, AUTOGEN sees parameter names as symbol assignments. AUTOGEN cannot equate a symbol to the corresponding system parameter unless it is spelled correctly. Look in AGEN$FEEDBACK.REPORT for any error messages AUTOGEN might have written.
- The value is correct: count the digits and make sure no commas are present.
- The parameter occurs only once in MODPARAMS.DAT.
- The parameter is not commented out.
For most parameters, if the new value is greater than the old value, you can accept AUTOGEN's setting. If the new value is less than the old value, HP recommends that you retain the old value because the system may not have been using that resource when running AUTOGEN.

For example, you might have used SYSMAN to increase GBLPAGES to 10,000 to accommodate layered products, but have not specified that change in MODPARAMS.DAT. AUTOGEN might calculate that the system needs only 5000 global pages. When you reboot after running AUTOGEN, not all of your layered products may be installed, and you might receive the system message GPTFULL, "global page table full," indicating that the system needs more GBLPAGES.

Repeat from step 3 until you are satisfied with the new parameter values.

If necessary, make further changes in MODPARAMS.DAT, run AUTOGEN again, and verify the changes as before. Usually after this second pass of AUTOGEN, the parameter values will be stable and you can then reboot.

Reboot. When you reboot, the system will use the new parameter values. Using AUTOGEN to reboot or rebooting right away is not necessary. However you must reboot before the system uses the new parameter values.

If the system does not boot, perform a conversational boot and use the backup parameter file you created in step 1:
```
SYSBOOT> USE SYS$SYSTEM:nodename_PARAMS_CURRENT.PAR
SYSBOOT> CONTINUE
```
When you enter the CONTINUE command, the system boots with the parameter values you saved before running AUTOGEN.

After the system has booted, if you want to use the old parameter values you can enter the following commands:
```
$ RUN SYS$SYSTEM:SYSMAN
SYSMAN> PARAMETERS USE SYS$SYSTEM:nodename_PARAMS_CURRENT.PAR
SYSMAN> PARAMETERS WRITE CURRENT
SYSMAN> EXIT
```

Run AUTOGEN using feedback regularly to ensure that the resources of your system match your system work load. For information about running AUTOGEN using feedback, see Modifying System Parameters with AUTOGEN.

Understanding the AUTOGEN Command Procedure