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  1. #1
    Join Date
    Oct 2012
    Posts
    33

    Unanswered: sybase memory config

    As far i understood,there is a parameter called "max memory" (In Sybase config file) with which the Sybase server runs.

    It depends on allocate shared memory.If it is set to 1,then full memory specified in "max memory" will be used for start up else only the needed memory will be used for starting sybase server.

    I have doubts with the following things,

    1.What is the max memory i should configure for 15.7 sybase ASE version(In order to start server properly)???

    2.Does Os shared memory determines sybase functionality???

    3.Am getting the below message when i start sybase server.


    00:0000:00000:00000:2012/12/06 13:07:52.54
    kernel Locking shared memory into physical memory.

    00:0000:00000:00000:2012/12/06 13:07:52.54
    kernel Could not allocate memory using Huge Pages. Allocated using regular pages. For better performance, reboot the server after configuring enough Huge Pages.

    00:0000:00000:00000:2012/12/06 13:07:52.54
    kernel os_create_region: cannot lock shared memory region '/opt/sybase/ASE-15_0/pqbsyb1.krg' into physical memory. System error: Cannot allocate memory.

    I dont know how to proceed after this.

    SO do i need to set Os shared memory to sum value before installation/starting server????


    Thanks!!!!!

  2. #2
    Join Date
    Jan 2004
    Posts
    545
    Provided Answers: 4
    If you know how much physical memory your server has you can substract an amount for the OS and other applications to use. The memory you have left you can use for ASE.
    If you configure Max Mem too high, and ASE tries to allocate everything startup will fail.

    For example: your server has 2Gb of physical memory, and the OS and other software needs 1Gb of memory, you can configure ASE with 1Gb max mem.
    If you set Allocate Shared Memory to 1, ASE will try to claim the full 1Gb at startup.
    However, if your OS and other software have claimed more than 1Gb, the 1Gb of max mem you configured for ASE isn't available and you will get an error.
    I'm not crazy, I'm an aeroplane!

  3. #3
    Join Date
    Oct 2012
    Posts
    33
    Hi..,
    Am using Linux server with 2GB physical memory(RHEL 5.7).

    How do i know how much of memory other process say,Os is using?

    What is the max memory i can set to overcome the error?

    00:0000:00000:00000:2012/12/10 06:59:28.89 kernel Could not allocate memory using Huge Pages. Allocated using regular pages. For better performance, reboot the server after configuring enough Huge Pages.
    00:0000:00000:00000:2012/12/10 06:59:28.89 kernel os_create_region: cannot lock shared memory region '/opt/sybase/ASE-15_0/pqbsyb1.krg' into physical memory. System error: Cannot allocate memory.


    But after this error, its not struck up.Sybase dataserver is running!!
    I heard that Sybase server wont start if it din't get the enough memory it needs.I have set the below one in Sybase config file.
    max memory = 500000

    Thanks!!

  4. #4
    Join Date
    Jul 2013
    Posts
    1
    Hi Forum,

    I've the problem.

    I'm going to migrate a system from a 12.5.4 sybase server to a 15.0.3 virtualized system.

    Both servers are running with 8 GB of memory, and 32bit.

    The 12.5.3 server is running with 3GB of max memory for sybase, and 1900MB of cache size in the default data cache.

    I've increased the max memory in the new server to 3 GB also (1572864 2k pages).

    When I increase the cache size from 900MB to 1500 MB the sybase server doesn't start anymore. In the sqlsrv.error.log appears the following message:

    "Could not allocate memory using Huge Pages. Allocated using regular pages."

    I've no huge pages configured in the system.

    Do you have any any idea what can be wrong?

    Some details below:


    Top output before changing setting

    ################################################## #############################

    Tasks: 93 total, 1 running, 92 sleeping, 0 stopped, 0 zombie
    Cpu0 : 0.0% us, 1.0% sy, 0.0% ni, 99.0% id, 0.0% wa, 0.0% hi, 0.0% si
    Cpu1 : 0.0% us, 0.0% sy, 0.0% ni, 100.0% id, 0.0% wa, 0.0% hi, 0.0% si
    Cpu2 : 0.0% us, 0.0% sy, 0.0% ni, 100.0% id, 0.0% wa, 0.0% hi, 0.0% si
    Cpu3 : 0.0% us, 0.0% sy, 0.0% ni, 100.0% id, 0.0% wa, 0.0% hi, 0.0% si
    Mem: 8305028k total, 6167528k used, 2137500k free, 54972k buffers
    Swap: 4200956k total, 0k used, 4200956k free, 5933128k cached

    ################################################## #############################



    vi SYBASE.cfg

    ################################################## #############################
    [Physical Memory]
    max memory = 1048576

    changed to

    [Physical Memory]
    max memory = 1572864
    ################################################## #############################


    After restarting the server successfully I’ve executed the sp_configure memory

    ################################################## #############################

    1> sp_configure memory
    2> go
    Msg 17411, Level 16, State 1:
    Server 'SYBASE', Procedure 'sp_configure', Line 322:
    Configuration option is not unique.

    Parameter Name Default Memory Used
    Config Value Run Value Unit
    Type
    ------------------------------ -------------------- -----------
    -------------------- -------------------- --------------------
    ----------
    additional network memory 0 0
    0 0 bytes
    dynamic
    allocate max shared memory 0 0
    0 0 switch
    dynamic
    compression memory size 0 76
    0 0 memory pages(2k)
    dynamic
    engine memory log size 0 2
    0 0 memory pages(2k)
    dynamic
    heap memory per user 4096 0
    4096 4096 bytes
    dynamic
    lock shared memory 0 0
    0 0 switch
    static
    max memory 49152 3145728
    1572864 1572864 memory pages(2k)
    dynamic
    memory alignment boundary 2048 0
    2048 2048 bytes
    static
    memory per worker process 1024 50
    2048 2048 bytes
    dynamic
    messaging memory 400 0
    400 400 memory pages(2k)
    dynamic
    pci memory size 32768 0
    32768 32768 memory pages(2k)
    dynamic
    shared memory starting address 0 0
    0 0 not applicable
    static
    total logical memory 49152 1479634
    739817 739812 memory pages(2k)
    read-only
    total physical memory 0 1479634
    0 739817 memory pages(2k)
    read-only

    (1 row affected)
    An additional 1666104 K bytes of memory is available for reconfiguration. This
    is the difference between 'max memory' and 'total logical memory'.
    (return status = 1)

    ################################################## #############################

    As you can see the system reports 1,5GB of unused memory

    But if I increase the cache size memory in the default data cache to 1500M, only using more 500MB, the system doesn’t start



    ################################################## #############################
    [Named Cache:default data cache]
    cache size = 924M

    changed to

    [Named Cache:default data cache]
    cache size = 1500M

    ################################################## #############################

    When I restart the server the following error appear regarding huge pages:

    00:00000:00000:2013/08/23 11:27:32.77 kernel SySAM: Using licenses from: /opt/sybase-15.0/SYSAM-2_0/licenses
    00:00000:00000:2013/08/23 11:27:32.82 kernel SySAM: Checked out license for 1 ASE_CORE (2013.09110/permanent/0E1A FBC9 0310 8C8C).
    00:00000:00000:2013/08/23 11:27:32.82 kernel This product is licensed to: SIEMENS AG, MEDICAL SOLUTIONS, an OEM license from Sybase, Inc.
    00:00000:00000:2013/08/23 11:27:32.82 kernel Checked out license ASE_CORE
    00:00000:00000:2013/08/23 11:27:32.82 kernel Adaptive Server Enterprise (Enterprise Edition)
    00:00000:00000:2013/08/23 11:27:32.83 kernel Using config area from primary master device.
    00:00000:00000:2013/08/23 11:27:32.85 kernel Could not allocate memory using Huge Pages. Allocated using regular pages. For better performance, reboot the server after configuring enough Huge Pages.
    00:00000:00000:2013/08/23 11:27:32.85 kernel Could not allocate memory using Huge Pages. Allocated using regular pages. For better performance, reboot the server after configuring enough Huge Pages.
    00:00000:00000:2013/08/23 11:27:32.85 kernel Attempt to attach shared memory (id 1867779) at address (nil), with flags 0 failed
    00:00000:00000:2013/08/23 11:27:32.85 kernel Cannot attach shared memory : error = 12 (Cannot allocate memory)
    00:00000:00000:2013/08/23 11:27:32.85 kernel os_create_region: shmat(1867779): Cannot allocate memory
    00:00000:00000:2013/08/23 11:27:32.86 kernel kbcreate: couldn't create server region 0.
    00:00000:00000:2013/08/23 11:27:32.86 kernel kistartup: could not create shared memory

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