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5 Replies Latest reply: Jun 29, 2012 7:09 AM by Levi-Pereira RSS

Configuring Oracle ASM 11gR2 to use ASMM

Dude! Guru
Currently Being Moderated
Hello,

Kernel hugepages under Oracle Linux is incompatible with Oracle AMM. The Oracle ASM instance under 11g uses AMM by default. So in order to configure Oracle ASM to use ASMM, what are the recommended settings please?

I reviewed http://docs.oracle.com/cd/E18283_01/server.112/e16102/asminst.htm#CHDBBIBF which outlines some information about various pool size parameters required for ASMM, depending on the size of the datafiles that will used.

But what about typical ASMM parametes like sga_target and pga_aggregate_target, or are these not used in an ASM instance?

How have you configred ASMM for Oracle ASM 11gR2?

Thanks!
  • 1. Re: Configuring Oracle ASM 11gR2 to use ASMM
    KuljeetPalSingh Guru
    Currently Being Moderated
    The minimum MEMORY_TARGET requirment for Oracle ASM is 256 MB. which we have set in ASM.

    But what about typical ASMM parametes like sga_target and pga_aggregate_target, or are these not used in an ASM instance?
    yes ,they will be used ,below snap from aix 6.1 OS
    SQL> sho parameter memory
    
    NAME                                 TYPE        VALUE
    ------------------------------------ ----------- ------------------------------
    memory_max_target                    big integer 272M
    memory_target                        big integer 272M
    
    SQL> r
      1* select * from V$MEMORY_DYNAMIC_COMPONENTS
    
    COMPONENT                         CURRENT_SIZE   MIN_SIZE   MAX_SIZE USER_SPECIFIED_SIZE OPER_COUNT LAST_OPER_TYP LAST_OPER LAST_OPER GRANULE_SIZE
    --------------------------------- ------------ ---------- ---------- ------------------- ---------- ------------- --------- --------- ------------
    shared pool                          201326592  201326592  201326592                   0          0 STATIC                                 4194304
    large pool                            20971520   12582912   20971520            12582912          2 GROW          IMMEDIATE 04-JUN-12      4194304
    java pool                                    0          0          0                   0          0 STATIC                                 4194304
    streams pool                                 0          0          0                   0          0 STATIC                                 4194304
    SGA Target                           264241152  255852544  264241152                   0          2 GROW          IMMEDIATE 04-JUN-12      4194304
    DEFAULT buffer cache                         0          0          0                   0          0 STATIC                                 4194304
    KEEP buffer cache                            0          0          0                   0          0 STATIC                                 4194304
    RECYCLE buffer cache                         0          0          0                   0          0 STATIC                                 4194304
    DEFAULT 2K buffer cache                      0          0          0                   0          0 STATIC                                 4194304
    DEFAULT 4K buffer cache                      0          0          0                   0          0 STATIC                                 4194304
    DEFAULT 8K buffer cache                      0          0          0                   0          0 STATIC                                 4194304
    
    COMPONENT                         CURRENT_SIZE   MIN_SIZE   MAX_SIZE USER_SPECIFIED_SIZE OPER_COUNT LAST_OPER_TYP LAST_OPER LAST_OPER GRANULE_SIZE
    --------------------------------- ------------ ---------- ---------- ------------------- ---------- ------------- --------- --------- ------------
    DEFAULT 16K buffer cache                     0          0          0                   0          0 STATIC                                 4194304
    DEFAULT 32K buffer cache                     0          0          0                   0          0 STATIC                                 4194304
    Shared IO Pool                               0          0          0                   0          0 STATIC                                 4194304
    PGA Target                            20971520   20971520   29360128                   0          2 SHRINK        IMMEDIATE 04-JUN-12      4194304
    ASM Buffer Cache                      25165824   25165824   25165824                   0          0 STATIC                                 4194304
    
    16 rows selected.
    Edited by: Kuljeet Pal Singh on Jun 27, 2012 6:59 PM
  • 2. Re: Configuring Oracle ASM 11gR2 to use ASMM
    Levi-Pereira Guru
    Currently Being Moderated
    Dude wrote:
    Hello,

    Kernel hugepages under Oracle Linux is incompatible with Oracle AMM. The Oracle ASM instance under 11g uses AMM by default. So in order to configure Oracle ASM to use ASMM, what are the recommended settings please?

    I reviewed http://docs.oracle.com/cd/E18283_01/server.112/e16102/asminst.htm#CHDBBIBF which outlines some information about various pool size parameters required for ASMM, depending on the size of the datafiles that will used.

    But what about typical ASMM parametes like sga_target and pga_aggregate_target, or are these not used in an ASM instance?

    How have you configred ASMM for Oracle ASM 11gR2?
    Hi Dude,

    The use of memory is related to the size of the database (Extent of ASM). i.e (Metadata only, no matter how big the database is, it's about extent).


    So there's not much to worry about the memory configuration on ASM. From 11.1 significant optimizations was done (introduced Variable Size Extents and allow change size of AU_SIZE) with respect to memory management, thus there is no need to set the SGA parameters on 11.1 or 11.2. ASM now leverages the MEMORY_TARGET parameter and the default of 272MB is more than enough for the ASM instance.

    Note that ASM’s SGA is not influenced or impacted by the number of database being serviced; i.e., ASM SGA does not need to scale when addtiional client databases are serviced.

    Each database store your ASM Extent Map on own SGA (i.e does not use ASM SGA), at time of startup of Database Instance, ASM load all Extend map of that database on Large Pool (ASM) and forward to SGA(Database), so from this time all extent is read only of SGA(Database).


    See this thread about extent:
    {message:id=10361947}

    Regards,
    Levi Pereira
  • 3. Re: Configuring Oracle ASM 11gR2 to use ASMM
    Dude! Guru
    Currently Being Moderated
    Thank you for trying to help.

    Btw, this is Oracle 11g ASM 11.2.0.2.0 x86_64 running on Oracle Linux 5.7 x86_64. Testing the setup under VirtualBox.

    @Kuljeet Pal Singh
    You are using ASM with AMM under AIX. But my question was how to I configure AMM using ASMM under Linux.

    So far I have not been able to find relevant documentation, other than "running AMM is recommended." But like I said, this won't fly with kernel hugepages.

    @Levi Pereira
    Ok, but how to I convert ASM from AMM to ASMM?

    <pre>

    </pre>

    Well, meanwhile I tried a few settings and made some "progress", though I have some strange results. Please see below:

    <pre>
    $ cd $ORACLE_HOME/dbs
    $ sqlplus / as sysasm

    SQL> sho parameter memory_target
    memory_target               big integer *272M*

    SQL> show parameter spfile
    +DATA/asm/asmparameterfile/registry.253.741750749

    SQL> create pfile from spfile;
    SQL> shutdown immediate

    $ cat init+ASM.ora
    +ASM.__oracle_base='/u01/app/oracle'#ORACLE_BASE set from in memory value
    *.asm_power_limit=1
    *.diagnostic_dest='/u01/app/oracle'
    *.instance_type='asm'
    *.large_pool_size=12M
    *.remote_login_passwordfile='EXCLUSIVE'
    </pre>

    Next, I modified the ASM init file to use ASMM.

    <pre>
    $ vi init+ASM.ora
    - add
    *.memory_target=0
    *.sga_target=272M
    *.sga_max_size=272M
    *.shared_pool_size=128M
    *.db_cache_size=64M
    *.pga_aggregate_target=30M
    </pre>

    And start the ASM instance using the init file instead of the pfile located in the dbs directory.

    <pre>
    $ sqlplus / as sysasm
    SQL> startup pfile=/u01/app/oracle/product/112/grid/dbs/init+ASM.ora
    ORA-00600: internal error code, arguments: [kmgsb_dependency_3], [2], [0].. etc.
    ORA-01078: failure in processing system parameters
    </pre>

    I tried a couple more times and using the exact same procedure it finally kicked in and I cannot reproduce the ORA-00600 error anymore. Strange.

    <pre>
    SQL> startup pfile=/u01/app/oracle/product/112/grid/dbs/init+ASM.ora
    ASM instance started

    Total System Global Area 283930624 bytes
    Fixed Size          2225792 bytes
    Variable Size          214595968 bytes
    ASM Cache          67108864 bytes
    ORA-15110: no diskgroups mounted

    SQL> sho parameter memory_target
    memory_target               big integer *0*
    </pre>

    So far so good, but why does it not find any diskgroups?

    Anyway, the complete setup seems dodgy to me. Why can I not find documentation about this?

    Edited by: Dude on Jun 27, 2012 9:01 AM
  • 4. Re: Configuring Oracle ASM 11gR2 to use ASMM
    Dude! Guru
    Currently Being Moderated
    Well, it seems I figured out the issue:

    Apparently I have been misinterpreting the information of AMM being incompatible with kernel hugepages. I was under the false impression that using /dev/shm or kernel hugepages was mutually exclusive, applying to the server, but it only applies to the DB instance.

    So the ASM instance using AMM and another instance using kernel hugepages with ASMM can coexist on the same server. There is no need to configure the ASM 11g instance to use ASMM too.

    For more details please see Understanding kernel hugepages and Oracle 11g AMM incompatibility

    It might explain why I couldn't find any information. Anyway, I'm closing this thread.
  • 5. Re: Configuring Oracle ASM 11gR2 to use ASMM
    Levi-Pereira Guru
    Currently Being Moderated
    Hi Dude,

    Sorry I misunderstood your question but get it, is clear.
    Glad you got the answer.

    Regards,
    Levi Pereira

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