This discussion is archived
11 Replies Latest reply: Sep 27, 2012 2:52 AM by user2709692 RSS

Heavy swapping observed on system

Neo-b Newbie
Currently Being Moderated
Hello All,

I am using Oracle 11gR2 on AIX 7.1.

I am seeing the below warning in my alert log file:
WARNING: Heavy swapping observed on system in last 5 mins.
pct of memory swapped in [187.54%] pct of memory swapped out [0.81%].
Please make sure there is no memory pressure and the SGA and PGA
are configured correctly. Look at DBRM trace file for more details.
My available RAM on the OS is 13.5 G and I configured the swap space to be 1.5 times the RAM, approximately 20G as recommended by Oracle.
My memory target is 6G.


1. First how could I look to the DBRM trace?
2. If my OS RAM is 13.5 G how much can I maximum increase my memory target ? I putted approximately to 40%~ 45% of total RAM
3. What action should be taken to resolve the above mentioned warning?

Regards,
  • 1. Re: Heavy swapping observed on system
    amardeep.sidhu Pro
    Currently Being Moderated
    Have a look at note 1452790.1.

    What does vmstat report ?

    How is the database health otherwise ?
  • 2. Re: Heavy swapping observed on system
    amardeep.sidhu Pro
    Currently Being Moderated
    1. First how could I look to the DBRM trace?
    The trace file will be there in your trace directory.

    http://bit.ly/Ix6iSq

    Check who are the top memory consumers.

    Edited by: amardeep.sidhu on Apr 29, 2012 1:28 PM
  • 3. Re: Heavy swapping observed on system
    Neo-b Newbie
    Currently Being Moderated
    As per Note 1452790.1 if I did not see ORA-4031/ORA-4030 then it is not an issue.

    However "pct of memory swapped in [*187.54%*]" Is it normal to see *187.54%* ?

    Still having the below question:

    2. If my OS RAM is 13.5 G how much can I maximum increase my memory target ? I putted approximately to 40%~ 45% of total RAM

    Regards,
  • 4. Re: Heavy swapping observed on system
    amardeep.sidhu Pro
    Currently Being Moderated
    Still having the below question:

    2. If my OS RAM is 13.5 G how much can I maximum increase my memory target ? I putted approximately to 40%~ 45% of total RAM
    In my opinion, before increasing the memory target you should investigate a bit that who are the consumers. One of the reasons could be PL/SQL as the the memory used by bulk operations can move beyond the value specified by pga_aggregate_target.

    Post the output of select name,value/1024/1024 "MB" from v$pgastat where name like '%PGA%';
  • 5. Re: Heavy swapping observed on system
    Neo-b Newbie
    Currently Being Moderated
    Hello,

    below is the result:
    SQL> select name, value/1024/1024 "MB" from v$pgastat where name like '%PGA%';
    
    NAME                                                                     MB
    ---------------------------------------------------------------- ----------
    aggregate PGA target parameter                                         2144
    aggregate PGA auto target                                        1704.66504
    total PGA inuse                                                  250.009766
    total PGA allocated                                               327.87207
    maximum PGA allocated                                            397.501953
    total freeable PGA memory                                              50.5
    PGA memory freed back to OS                                            4436
    total PGA used for auto workareas                                         0
    maximum PGA used for auto workareas                               56.859375
    total PGA used for manual workareas                                       0
    maximum PGA used for manual workareas                            .263671875
    
    11 rows selected.
    My question is in general how much can I increase my memory target ? what percentage of total RAM can reach ?

    Regards,
  • 6. Re: Heavy swapping observed on system
    amardeep.sidhu Pro
    Currently Being Moderated
    PGA usage sounds ok to me.
    My question is in general how much can I increase my memory target ? what percentage of total RAM can reach ?
    Assuming that apart from Oracle database nothing else runs on the server, leaving the part that OS needs aside (A minimum of 4-5 GB i think. Sysadmin can give you a better idea about this) the rest you can give to Oracle.
  • 7. Re: Heavy swapping observed on system
    Neo-b Newbie
    Currently Being Moderated
    Ok thanks.

    So can I ignore this warning in your opinion ? "Heavy swapping observed on system"

    Regards,
  • 8. Re: Heavy swapping observed on system
    amardeep.sidhu Pro
    Currently Being Moderated
    I think you should speak to your system admin, analyse the output of utilities like vmstat and observe the top memory consumers. Then decide if any action needs to be taken.
  • 9. Re: Heavy swapping observed on system
    jeff81 Newbie
    Currently Being Moderated
    I started receiving this same message right after I applied the April CPU on my Windows x64 2003 R2 and 2008 R2 servers running 11.2.0.2. I opened an SR to see if it is a non issue.
  • 10. Re: Heavy swapping observed on system
    798431 Newbie
    Currently Being Moderated
    Hello Jeff

    I get the same message right after I applied the Juli CPU on my Windows x64 2008 R2 standard running 11.2.0.2
    did you get any reply from your SR if it is was non issue ?
  • 11. Re: Heavy swapping observed on system
    user2709692 Newbie
    Currently Being Moderated
    I see similar messages in the Alert-Log, they also started after applying the July CPU on Oracle 11.2.0.2. The database runs on Windows Server 2008 R2 with 32GB RAM installed. memory_target ist 8G, memory_max_target ist 12G. The database installarion and the database files reside on a storage area network (SAN). The numbers seem to be ridicoulous, i.e. "pct of memory swapped in [4515164.17%] pct of memory swapped out [51220.00%]".

Legend

  • Correct Answers - 10 points
  • Helpful Answers - 5 points