When you install or upgrade the OpenVMS operating
system, the system executes the AUTOGEN.COM procedure to set the values
of system parameters and the sizes of the page, swap, and dump files
according to the system configuration.
After running your system for at least 24 hours
with users or a typical application workload on the system, run the
AUTOGEN.COM procedure again to tune the system properly. Run AUTOGEN
as follows. (In an OpenVMS Cluster, you must follow these steps to
run AUTOGEN on each cluster node.)
Run
AUTOGEN in feedback mode, examine AGEN$PARAMS.REPORT, and reboot the
system. To run AUTOGEN in feedback mode, use the following command:
To view AGEN$PARAMS.REPORT
on your screen, enter the following command:
$ TYPE SYS$SYSTEM:AGEN$PARAMS.REPORT
You can print this file or examine it using the
EDIT/READ_ONLY command.
If the report includes a message similar to the
following, you might need to modify the size of the page, swap, or
dump file:
%AUTOGEN-W-DSKSPC, The disk on which DKA0:[SYS0.SYSEXE]PAGEFILE.SYS
resides would be over 95% full if it were modified to hold 20000 blocks.
For more information about AGEN$PARAMS.REPORT,
see the HP OpenVMS System Manager's Manual, Volume 2: Tuning,
Monitoring, and Complex Systems.
Run
AUTOGEN again in feedback mode two work days later and examine AGEN$PARAMS.REPORT,
and then reboot the system. (For information about the importance
of having a current AGEN$FEEDBACK.DAT file, see Section 4.8.)
HP
recommends that you run AUTOGEN from the SAVPARAMS phase through the
TESTFILES phase weekly thereafter until the system stabilizes (that
is, until AUTOGEN finds nothing that needs to be adjusted). Make
sure you run AUTOGEN when your system is running under a typical workload.
Examine AGEN$PARAMS.REPORT to determine the need for additional changes.
IMPORTANT: If you start AUTOGEN without specifying the execution-mode
parameter (FEEDBACK, NOFEEDBACK, or CHECK_FEEDBACK), AUTOGEN uses
the feedback information in its calculations. However, if the feedback
information reflects system up time of less than 24 hours, or if the
feedback information is more than 30 days old, AUTOGEN includes warnings
in the AGEN$PARAMS.REPORT file to alert you to potential problems
with the feedback data. If you wrongly assume the feedback is valid,
the parameter settings might vary significantly from your expectations.
If you specify FEEDBACK (or NOFEEDBACK), AUTOGEN
uses (or does not use) the feedback regardless of the data’s
reliability. AUTOGEN proceeds through the SETPARAMS phase (if you
specified SETPARAMS, SHUTDOWN, or REBOOT as the end phase) and sets
system parameters to the values it computed.
If you specify CHECK_FEEDBACK, AUTOGEN checks
the validity of the feedback data. If AUTOGEN determines the feedback
is suspect, then AUTOGEN ignores the feedback when computing parameter
values. It stops at the TESTFILES phase and issues a warning in the
report that parameters have not been changed. You must read the report
and decide whether the calculated values are acceptable. You can
either use them (by running the AUTOGEN SETPARAMS phase) or rerun
AUTOGEN with valid feedback data.
After
the system has stabilized, HP recommends that you run AUTOGEN at least
monthly to save feedback information for future use. Use the following
command:
$ @SYS$UPDATE:AUTOGEN SAVPARAMS
If you do not maintain current feedback information
for AUTOGEN, you will not have the needed information the next time
you upgrade your system. As a result, you may have to reboot and
rerun AUTOGEN several times to make your upgraded system operational.
For more information about running AUTOGEN, see
the HP OpenVMS System Manager's Manual, Volume 2: Tuning,
Monitoring, and Complex Systems.
