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2 Replies Latest reply: Aug 9, 2013 3:30 AM by Mr.D. RSS

I/O question

Mr.D. Explorer
Currently Being Moderated

Hi,

i've a two node 11.2 Rac database on Win 2008R2 64bit server using ASM.

  • 1. Re: I/O question
    Mr.D. Explorer
    Currently Being Moderated

    In both nodes there aren't high workload.

    In the first instance top wait is  direct path read with avg(ms)=72 and 65.9% time

    In the second instance the only wait I/O is sequential read with avg=9 and 23.7%  time

     

    First instance:

                                                              Avg

                                                              wait  % DB

    Event                                Waits    Time(s)  (ms)  time Wait Class

    direct path read                    79,219      5,722    72  65.9 User I/O

     

    Second instance:

                                                              Avg

                                                              wait  % DB

    Event                                Waits    Time(s)  (ms)  time Wait Class

    db file sequential read              82,642        742      9  23.7 User I/O

     

     

     

    Looking File IO Stats of the first instance:


                    Av      Av    Av                      Av    Buffer  Av Buf

            Reads Reads/s  Rd(ms) Blks/Rd      Writes Writes/s      Waits  Wt(ms)

    -------------- ------- ------- ------- ------------ -------- ---------- -------

    MYDATA                  +DATA/mydb/datafile/MYDATA.256.782756789

            48,409      0    14.1    30.2        9,452        0          0    0.0

    MYIDX                    +INDICI/mydb/datafile/MYIDX.256.782752235

            23,654      0    23.5    24.5      24,718        0          0    0.0

    SYSAUX                  +SISTEMA/mydb/datafile/sysaux.264.782739385

            20,027      0    17.8    8.6      22,550        0          3    0.0

    SYSTEM                  +SISTEMA/mydb/datafile/system.263.782739377

          211,057      2    2.9  111.8        4,739        0        23    0.4

    TEMP                    +SISTEMA/mydb/tempfile/temp.266.782739391

                50      0    32.0    2.7          56        0          0    N/A

    UNDOTBS1                +SISTEMA/mydb/datafile/undotbs1.265.782739391

            6,427      0    51.9    63.6        9,233        0        51    0.4

    UNDOTBS2                +SISTEMA/mydb/datafile/undotbs2.268.782739403

              508      0    91.2    61.8          17        0          0    0.0

    USERS                    +SISTEMA/mydb/datafile/users.269.782739403

                49      0    85.9    26.7          17        0          0    0.0

     


    Seems to be high (23.5, 17.8, 51 for the undo).

    The second instance do not suffers of this problems.


    Tablespace              Filename

    ------------------------ ----------------------------------------------------

                    Av      Av    Av                      Av    Buffer  Av Buf

            Reads Reads/s  Rd(ms) Blks/Rd      Writes Writes/s      Waits  Wt(ms)

    -------------- ------- ------- ------- ------------ -------- ---------- -------

    MYDATA                  +DATA/mydb/datafile/MYDATA.256.782756789

            60,113      0    3.9    2.8      11,303        0          0    0.0

    MYIDX                    +INDICI/mydb/datafile/MYIDX.256.782752235

            37,746      0    8.7    1.6      28,367        0          0    0.0

    SYSAUX                  +SISTEMA/mydb/datafile/sysaux.264.782739385

            31,862      0    10.3    2.4      21,070        0          0    0.0

    SYSTEM                  +SISTEMA/mydb/datafile/system.263.782739377

            11,725      0    6.0    1.0        3,947        0        23    0.9

    TEMP                    +SISTEMA/mydb/tempfile/temp.266.782739391

                73      0    7.9    34.3          120        0          0    N/A

    UNDOTBS1                +SISTEMA/mydb/datafile/undotbs1.265.782739391

                14      0    0.0    1.0          14        0          1    0.0

    UNDOTBS2                +SISTEMA/mydb/datafile/undotbs2.268.782739403

                72      0    7.1    1.0        9,982        0        20    0.0

    USERS                    +SISTEMA/mydb/datafile/users.269.782739403

                15      0    2.7    1.0          14        0          0    0.0

     


    So what can i check?

  • 2. Re: I/O question
    Mr.D. Explorer
    Currently Being Moderated

    Hi,

    i found the problem.

    It's caused by ORACLE.EXE(SHAD) process that consume high cpu due to bug.

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