How do I configure the UNIX Kernel when using the Shared Cache option?

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    This document contains official content from the BMC Software Knowledge Base. It is automatically updated when the knowledge article is modified.


    PRODUCT:

    Remedy AR System Server


    APPLIES TO:

    BMC Remedy AR System Server



    QUESTION:

    In using the shared cache option, what are the basic setup for the UNIX Kernel Configuration?


    ANSWER:

     

    Legacy ID:KA319072

    UNIX Kernel Configuration for Shared Cache 
    ---------------------------------------------------------------------- 
    In order to use shared memory, you must configure the UNIX kernel. The settings below are derived from the various database manuals (mostly Sybase and Oracle) that define the recommended kernel configuration values. When one database vendor recommends a higher value than the other, the higher value is used. The values are applied across all UNIX platforms. After any of these system changes, you MUST reboot the operating system. You need to add additional shared memory allocated to your database configuration when using shared cache for the AR System memory segments. 

    **NOTE: Consult your UNIX documentation. The values given here are just examples and Remedy Corporation will not support UNIX Kernal configuration issues. ** 


    Warning on Making Kernel Configuration Changes  
    ------------------------------------------------------------------------------- 
    Changing kernel parameters to improper or inappropriate values or combinations of values can cause data loss, system panics, or other (possibly very obscure and/or difficult to diagnose) operating anomalies, depending on which parameters are set to what values. 
    ¨ Before altering the value of any configurable kernel parameter, be sure you  
    know the implications of making the change. 
    ¨ Never set any system parameter to a value outside the allowable range for that  
    parameter. 
    ¨ Many parameters interact, and their values must be selected in a balanced way. 

    ****NOTE: Please refer to your operating system documentation or technical support. Remedy Corporation assumes no responsibility for UNIX Kernel configuration support.******** 

    VI. Sample IPC Semaphores and Shared Memory Setup 
    IPC Semaphores 
    Name Value Description 
    semaem 16,384 Max value for adjusted on exit semaphores 
    semmap 64 Max number of semaphore map entries 
    semmni 100 Number of semaphore identifiers 
    semmns 2,048 Max number of semaphores  
    semmnu 200 Number of semaphores undo structures 
    semume 64 Semaphore undo entries per process 
    semvmx 32,767 Semaphore maximum value 
    semmsl 100 Max semaphores per id 
    semopt 10  
    semusz 96 

    IPC Shared Memory 
    Name Value Description 
    shmmax 805,306,368 Max shared memory segment in bytes 
    shmmni 200 Number of shared memory identifiers 
    shmseg 120 Shared memory segments per process 
    shmmin 1 Minimum shared memory segment size 


    Sample Solaris Setup (/etc/system) 
    forceload:sys/semsys 
    forceload:sys/shmsys 
    maxusers=255 
    set shmsys:shminfo_shmmax=805306368  
    set shmsys:shminfo_shmmin=1  
    set shmsys:shminfo_shmmni=100 
    set shmsys:shminfo_shmseg=32 
    set semsys:seminfo_semaem=16384 
    set semsys:seminfo_semmap=64 
    set semsys:seminfo_semmni=100 
    set semsys:seminfo_semmns=2048 
    set semsys:seminfo_semmnu=200 
    set semsys:seminfo_semmsl=100 
    set semsys:seminfo_semopm=10 
    set semsys:seminfo_semume=64 
    set semsys:seminfo_semusz=96 
    set semsys:seminfo_semvmx=32767 



     


    Article Number:

    000030256


    Article Type:

    FAQ/Procedural



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