Configuring memory allocation for IBM WebSphere Application Server (AIX)

On AIX®, the LDR_CNTRL environment variable controls the way AIX handles the memory space available to programs and the page sizes used in each segment. To provide sufficient memory allocation for WebSphere® Application Server, you must unset this environment variable for WebSphere Application Server to run correctly.

About this task

If your installation includes a stand-alone instance of WebSphere Application Server, unset the LDR_CNTRL environment variable on the computer on which WebSphere Application Server is installed. For cluster environments, you must unset the LDR_CNTRL environment variable on each computer where WebSphere Application Server is installed (Deployment Manager and managed nodes). The change can be permanently configured if appropriate for your environment.

Procedure

To unset the LDR_CNTRL environment variable:

  1. Make sure all WebSphere Application Server processes are stopped.
  2. Configure the LDR_CNTRL environment variable.
    Refer to your system administrator if you are unsure about this process.

    The following example shows how to unset the LDR_CNTRL environment variable if your login shell is /bin/bash.

    • To apply the setting to all users on the system, add the following line to the /etc/profile file:
      unset LDR_CNTRL
    • To apply the setting to a specific user, add the line to the ~/.profile file for the user. The user to configure is typically root unless you reconfigured WebSphere Application Server for non-root administration.
    If you do not want to permanently configure the environment variable as shown in the example, you can run the unset LDR_CNTRL command just before you start a WebSphere Application Server process. All WebSphere Application Server processes must be stopped before you run these commands.
  3. Start the WebSphere Application Server processes.
  4. In a clustered environment, repeat this procedure on all computers where WebSphere Application Server is installed.