HP OpenVMS Version 8.3 Upgrade and Installation Manual > Chapter 7 After Installing or Upgrading the OpenVMS Operating System

Tuning BAP System Parameters (Alpha Upgrade Only)

  Table of Contents



OpenVMS Alpha Version 7.1 and later contains system parameters that control the operation of bus-addressable pool (BAP).

The CIPCA, CIXCD, KFMSB, and Qlogic ISP 1020 (KZPSM-AA) adapters are some of the adapters that use bus-addressable pool to improve performance. BAP is a non-paged dynamic, physical-address-filtered memory pool used to overcome I/O bus and 32-bit adapter physical addressing limits.

The following table lists the BAP system parameters and their default values:

System ParameterDefault Value









The default values of these parameters enable the system to boot with any configuration. When AUTOGEN is run on a configured system, it resets these parameters to values that should enhance performance for the current system configuration.

If this is an upgrade of OpenVMS, or if the system fails to boot after a hardware change and displays a message that refers to incorrect BAP parameters, HP recommends that you perform the following steps:

  1. To begin the conversational boot, use the BOOT command in the following format:

    BOOT -FLAGS 0,1 [device-name]

    For device-name, substitute the device name of your system disk drive from which you want to boot. For example, if the system disk has a device name of DKA400, enter the following command and press the Enter key:

       >>> BOOT -FLAGS 0,1 DKA400
  2. At the SYSBOOT> prompt, enter the following:

      NPAG_BAP_MIN 0
      NPAG_BAP_MAX 0
      NPAG_BAP_MAX_PA -1

  3. This should enable the system to boot. Once completed, enter the following command:

  4. The command entered in the preceding step creates a file that will contain the BAP values for the system in its current configuration. To see what they are, enter the following command (the BAP parameters in AGEN$FEEDBACK.DAT do not include the NPAG_ prefix):

  5. Check MODPARAMS.DAT for any hardcoded BAP values by entering the following command:

IMPORTANT: If any BAP parameters are defined in MODPARAMS.DAT, HP strongly recommends removing them. Their presence in MODPARAMS.DAT could be the source of the current boot problem or might be a source of one in the future if a change is made to the adapter card configuration in the system.

If you make changes to adapters in the future and the system boots successfully, immediately run AUTOGEN, by entering the following command: