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  1. #1
    Join Date
    Nov 2005
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    Exclamation Unanswered: explanation/help on DB2_FMP_COMM_HEAPSZ

    Hey gang,

    I have a question and hopping someone will be able to explain this one.

    most of our boxes running UNIX 6.1.0.0, however we do have a few with Linux x86_64 x86_64 x86_64 GNU/Linux

    Sometime back before I got here someone has unset DB2_FMP_COMM_HEAPSZ everywhere and all looked good until I started looking more into the LINUX boxes.

    On UNIX box we can run SQL against SYSIBMADM.REG_VARIABLES and not have a problem, but on the LINUX box it trows this error

    SQL1042C An unexpected system error occurred. SQLSTATE=58004

    I have recently upgraded db2 level on LINUX boxes to DB2 v9.7.0.6. went back and confirmed that upgrade output files has no errors, so all is good.

    Checked db2diag and sure enough I see this in there:"MESSAGE : ADM11001E DB2 did not create a memory segment for running fenced routines. This was specified by the use of DB2_FMP_COMM_HEAPSZ registry variable."

    Looked it up on the IBM site and it says:"
    Operating system: Windows, UNIX"

    Which means this registry variable should not even play a role on LINUX box. I have set it now to DB2_FMP_COMM_HEAPSZ=20 and all is good again.

    Do I just brush it off as IBM documentation mistake and just remember going forward that this registry needs to be set on LINUX and not on UNIX, or there is a bigger problem that I am missing?

    Thank you
    --
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows

    DB2 v9.7.0.6 os 6.1.0.0

  2. #2
    Join Date
    Jan 2003
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    Provided Answers: 5
    I think you can attest it to misunderstanding the documentation. When IBM references UNIX as an OS with respect to DB2, it means all UNIX based OSes (AIX, LINUX, etc). See there is no OS that DB2 runs on named "UNIX". IBM uses it as a catchall.

    Andy

  3. #3
    Join Date
    Nov 2005
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    Andy

    I hope you are right. Here is why I am still not convinced.

    Looking at IBM DB2 9.7 Information Center for Linux, UNIX, and Windows

    and start checking out some of the variables you will clearly see that some are listed strictly for LINUX i.e. DB2_MIN_IDLE_RESOURCES
    DB2_MIN_IDLE_RESOURCES
    • Operating system: Linux

    while others are listed for ALL and some are only for UNIX

    DB2_NUM_CKPW_DAEMONS
    • Operating system: UNIX

    and there are others like this that list most but UNIX
    DB2_RESOLVE_CALL_CONFLICT
    • Operating system: AIX, HP-UX, Solaris, Linux, Windows



    Unless I am misreading what you are saying
    --
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows

    DB2 v9.7.0.6 os 6.1.0.0

  4. #4
    Join Date
    Jan 2003
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    Provided Answers: 5
    I do not know if you are misreading what I said. I will try again.

    When DB2 mentions in its documentation "UNIX", it means all unix derivatives (LINUX, AIX, Solaris, etc). If it mentions a specific OS (e.g. LINUX) then it is only valid for that OS. I realize that sometimes DB2 will list all the OSes out (e.g. AIX, LINUX, SOLARIS). I do not know why they do this, but my guess is that at one point the option was only for one or two of those and support was added for other OSes later, so they just added the new OS name to the list, and then never bothered collapsing the list to UNIX when all derivatives were supported.

    Andy

  5. #5
    Join Date
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    ok. how do you explain that I am able to run against SYSIBMADM.REG_VARIABLES on UNIX with this variable not set, but not on LINUX.
    --
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows

    DB2 v9.7.0.6 os 6.1.0.0

  6. #6
    Join Date
    Jan 2003
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    Provided Answers: 5
    By Unix, I assume you mean AIX. Did you read the documentation for this parameter? Is says the default is 20MB, but on AIX it is 256MB. My guess is that the default is too small for Linux but OK for AIX.

    Andy

  7. #7
    Join Date
    Aug 2008
    Location
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    You got ADM11001E with DB2_FMP_COMM_HEAPSZ not set / 20MB (default). Then, you set it to 20MB and restarted the instance. Right? So, it's still the same value - 20MB. I think restart cleaned-up some fmp processes, so the error has disappeared but it may come back again...

  8. #8
    Join Date
    Jun 2003
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    Provided Answers: 1
    Quote Originally Posted by db2girl View Post
    Then, you set it to 20MB
    DB2_FMP_COMM_HEAPSZ=20 means 80 KB (20 4 KB pages), not 20 MB, if I'm not mistaken.
    ---
    "It does not work" is not a valid problem statement.

  9. #9
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    Quote Originally Posted by n_i View Post
    DB2_FMP_COMM_HEAPSZ=20 means 80 KB (20 4 KB pages), not 20 MB, if I'm not mistaken.
    Oops, you're right. He set it to 20, not 20MB.

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