Preparing to Install PL/I

To check the values of your system parameters, enter the following command at the DCL prompt to invoke the System Generation Utility (SYSGEN):

$ RUN SYS$SYSTEM:SYSGENReturn
SYSGEN>

At the SYSGEN> prompt, enter the SHOW command to display the value of a system parameter. The values displayed should equal or exceed the value of each system parameter listed in Table 1.2, “Required Minimum Values for System Parameters”, unless the compiler is not currently installed as a known image or to be installed as a known image after the installation. The following example displays the current value of the GBLPAGES system parameter:

SYSGEN> SHOW GBLPAGESReturn

After checking the parameters with the SHOW command, enter the EXIT command at the SYSGEN> prompt to return to DCL level.

To determine the number of free global pages on your system, invoke the OpenVMS Install Utility, as follows:

$ INSTALL Return

INSTALL> LIST/GLOBAL/SUMMARY Return

        Summary of Local Memory Global Sections

309 Global Sections Used,  28866/13134 Global Pages Used/Unused

INSTALL> EXIT Return

When you enter these commands, the system displays a summary of the number of global sections used and the number of global pages used and unused (free). To exit from the OpenVMS Install Utility, use the EXIT command.

PL/I requires the minimum number of free global pages indicated in Table 1.2, “Required Minimum Values for System Parameters”. If the number of free pages is less than the required minimum in Table 1.2, “Required Minimum Values for System Parameters”, you can use the OpenVMS Install Utility to delete an existing known image. You also can increase the maximum value of the GBLPAGES system parameter, a parameter that establishes the limit on the total number of global pages that can be created. To increase this limit, use the OpenVMS System Generation Utility (SYSGEN) to edit the file SYS$SYSTEM:MODPARAMS.DAT. Then invoke the AUTOGEN command procedure, SYS$UPDATE:AUTOGEN.COM. For more information on the AUTOGEN command procedure, see your processor-specific installation/operations guide.

To determine the number of free global sections, first invoke SYSGEN as follows:

$ RUN SYS$SYSTEM:SYSGEN Return
SYSGEN> USE CURRENT Return
SYSGEN> SHOW GBLSECTIONS Return

 Parameter name     Current  Default  Minimum Maximum  Unit  Dynamic
 --------------     -------  -------  ------- -------  ----  -------
 GBLSECTIONS            512      250       20    4095  Sections


SYSGEN> EXIT Return

The last number displayed is the maximum number of global sections that can be made known to the OpenVMS operating system (the maximum number of global sections that you can set). Use the OpenVMS Install Utility to determine the number of global sections that are in use. Add the number that are in use to the minimum that must be free to install PL/I (indicated in Table 1.2, “Required Minimum Values for System Parameters”). If the sum exceeds the maximum number of global sections that you can set, then increase the number of free global sections until you have enough free to install PL/I. To increase the maximum value of the GBLSECTIONS system parameter, use SYSGEN to edit the file SYS$SYSTEM:MODPARAMS.DAT. Then invoke the SYS$UPDATE:AUTOGEN.COM procedure. For more information on the AUTOGEN.COM procedure, see your processor-specific installation/operations guide.

If the number of global sections used plus the number provided in Table 1.2, “Required Minimum Values for System Parameters” is less than the maximum number of global sections, you can exit from SYSGEN and continue.

A simpler method of finding the number of free global sections and pages available on your system is to use the WRITE command with the F$GETSYI lexical function. The following example shows how to display this information at your terminal (the default device for SYS$OUTPUT):

$ WRITE SYS$OUTPUT F$GETSYI ("FREE_GBLPAGES") Return
15848
$ WRITE SYS$OUTPUT F$GETSYI ("FREE_GBLSECTS")Return
24

If the values displayed by the system are greater than the values in Table 1.2, “Required Minimum Values for System Parameters”, you need not increase the values for these parameters. If the value of free global pages or global sections is less than the value in Table 1.2, “Required Minimum Values for System Parameters”, increase the maximum values of the GBLPAGES and GBLSECTIONS system parameters.

Section 1.4.2.3, “Changing System Parameter Values with AUTOGEN” describes the procedures for increasing these values as well as those of other system parameters. See the OpenVMS documentation on system management and operations for more information.

Use the AUTOGEN command procedure to change system parameters. AUTOGEN automatically adjusts values for parameters that are associated with the ones you reset manually. To change system parameters with AUTOGEN, edit the following file:

SYS$SYSTEM:MODPARAMS.DAT

For example, to change the setting for the WSMAX system parameter, add to the file:

WSMAX = 1024

To change the setting for incremental SYSGEN parameters, add to the file:

ADD_GBLPAGES = 2000

Then run the AUTOGEN procedure to recalculate your system parameters. Enter the following command at the DCL prompt:

$ @SYS$UPDATE:AUTOGEN GETDATA REBOOTReturn

AUTOGEN performs an automatic system shutdown and reboots when it has finished. Rebooting your system makes the new parameter values active. You may also wish to add the [NO]FEEDBACK parameter to the AUTOGEN command line.