HP BA322 90087 - Manual (Page 164)

7.25 Modifying System Parameters
Based on your examination of AGEN$PARAMS.REPORT, you might need to modify parameter
values in MODPARAMS.DAT. Read the notes in
Section 7.25.1 (page 164) . These notes apply to
modifications being made after a new installation and after an upgrade. If you are modifying
system parameters after an upgrade, also see
Section 7.25.2 (page 164) .
7.25.1 General Notes About Modifying System Parameters
When modifying system parameters, note the following:
• In general, let AUTOGEN calculate system parameters. You can hardcode values (such as
GBLPAGES=value), but doing so overrides AUTOGEN and might not allow it to set an
optimal value based on observed usage.
• Whenever possible, use MIN_parameter values (such as MIN_GBLPAGES) to set the minimum
value that can be set for a parameter by AUTOGEN. AUTOGEN increases the value if
necessary. It also adjusts related parameters unless they are hardcoded, in which case
information is provided in the AGEN$PARAMS.REPORT file. Use MAX_parameter values
to set a maximum value when it is necessary to limit a parameter to a known maximum
value (this is rarely necessary).
• Enter numeric values as integers without commas (for example, 10000). Enter alphabetic
characters in lower or uppercase.
• HP recommends that you include comments in the MODPARAMS.DAT file indicating who
changed the value, when it was done, and why it was done. An exclamation point (!) serves
as a comment starter and can appear anywhere on a line. The following example illustrates
the modifications recommended in the preceding bulleted items:
! the following changes made by K.Newcomb on 9/20/03
!
SWAPFILE=0 ! don’t re-size the SWAPFILE on AUTOGEN runs
MIN_gblsections=750 ! required for DECwindows MOTIF
MIN_NPAGEDYN=2750000 ! set npagedyn to a min of 2.75 million
For more information about the MODPARAMS.DAT file and about using AUTOGEN in general,
see the HP OpenVMS System Manager's Manual, Volume 2: Tuning, Monitoring, and Complex Systems.
7.25.2 Modifying System Parameters After an Upgrade
Review the file SYS$SYSTEM:MODPARAMS.DAT. The upgrade procedure created a new version
of this file. The old version is named SYS$SYSTEM:MODPARAMS.DAT_OLD. The new
MODPARAMS.DAT file contains all the parameters in the old file, plus various parameters that
the upgrade procedure added to ensure that all necessary system parameters are properly
propagated from the earlier version of OpenVMS. The upgrade procedure also adds comment
lines to explain the source of the parameters in each section of the new MODPARAMS.DAT file.
Note that the old MODPARAMS.DAT is included in the new MODPARAMS.DAT each time an
upgrade is performed. Because of this, if MODPARAMS.DAT is not reviewed and cleaned up
after each upgrade, it might eventually contain many levels of duplicated parameters. For this
reason, you should review MODPARAMS.DAT after each upgrade. This enables you to eliminate
any duplication. You can also take this opportunity to modify any parameters, if necessary.
Based on your examination of AGEN$PARAMS.REPORT, you might need to modify parameter
values in MODPARAMS.DAT.
The following subsections are examples of instances where you need to modify parameters in
MODPARAMS.DAT.
164 After Installing or Upgrading the OpenVMS Operating System