Configuring the shared memory and semaphores

On each managed system, shared memory and semaphores are required for data collection. The Agent requires one semaphore and one shared memory segment for each metric group per instance (instance refers to a system or an application collector). The default values of shared memory and semaphores are usually sufficient. 

If you are notified about inadequate shared memory and semaphore resources during Agent installation, configure the following settings:

To configure UNIX and Solaris systems

  1. Log in as a root user to the computer where the Continuous Optimization Agent is installed.
  2. Open the /etc/system file and update values as described in the following table:



    Recommendation for specifying a value


    semsys: seminfo_semmni

    Number of semaphore identifiers (semaphore sets) systemwide.

    Add (25 + 25 x the number of instances) to the current value.

    (An instance refers to a system or an application collector. Number of instances refers to the number of system and application collectors running on a computer.)

    If the current value of the computer is 100 and you have one system collector, set the value to 150.

    semsys: seminfo_semmsl

    Maximum number of semaphores per unique identifier.

    No specific recommendation.

    Not applicable

    semsys: seminfo_semopmNo specific recommendation.No specific recommendation.Not applicable


    Ensure that the variable entries in the /etc/system file does not exceed 80 characters because the kernel might get disabled.

  3. Restart the computer for these updates to take effect.

To configure Linux systems

  1. Log in as a root user to the Linux system where the Continuous Optimization Agent is installed.
  2. Access the following path that contains the kernel settings files: /proc/sys/kernel
  3. Update values in the following files as required: sem, shmall, shmmax, shmmni


    These updates affect the Linux kernel settings. Therefore, read the Linux documentation carefully before updating these files.

  4. Run the following command to check the shared memory settings:
    ipcs -l

  5. Restart the computer.

To configure HP systems

  1. Log in to the HP-UX computer where the Agent is installed.
  2. At the UNIX prompt, enter the following command to open System Management Homepage (SMH).
  3. Select k -Kernel Configuration.
  4. Select t - Tunables to view a list of configurable parameters.
  5. Select the parameter that you want to update.
  6. Press m and specify the updated values for the required parameters.
    A confirmation message about these modifications is displayed.
  7. Restart the computer.

For more information, see  Kernel Parameters Configuration Open link .

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