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  1. #1
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    Unanswered: Purescale start without other hosts

    Hello everyone,

    I have a purescale DB2v10.1.0.2 installed on two RHEL hosts. Host CF1 has Primary CF and member 1, host CF2 has Peer CF and member 2.

    The question is how can I start DB2 if only CF1 is online (CF2 powered off)? When CF2 is offline then GPFS shared filesystems are not getting mounted and all data/shared_sql directories are not available.

  2. #2
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    Provided Answers: 1
    What does "db2cluster -cm -list -tiebreaker" say?
    ---
    "It does not work" is not a valid problem statement.

  3. #3
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    I shall try it when I have maintenance window.

  4. #4
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    Why do you need a maintenance window for listing the cluster configuration?
    ---
    "It does not work" is not a valid problem statement.

  5. #5
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    I thought you meant to issue the command when CF2 is offline. The result is:

    [db2sdin1@cf1 ~]$ db2cluster -cm -list -tiebreaker
    The current quorum device is of type Disk with the following specifics: WWID=360050768028087faf80000000000000c.
    [db2sdin1@cf1 ~]$
    This is a WWID of tiebreaker disk on FC storage.
    Last edited by xat; 04-03-13 at 16:25. Reason: add clarification

  6. #6
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    Can you explain in detail the sequence of your actions: "how can I start DB2 if only CF1 is online (CF2 powered off)? When CF2 is offline then GPFS shared filesystems are not getting mounted"? How did CF2 go offline? How do you mount the file systems?
    ---
    "It does not work" is not a valid problem statement.

  7. #7
    Join Date
    May 2003
    Location
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    Maybe I am missing something, but if there are two physical servers, and each physical server has one member and one CF (each in its own LPAR), then the pureScale cluster should work with only one physical server working (and both LPARs booted). There is a db2start command for the CF just like there is for a member. for example:
    db2start CF 128 (should start CF1)

    I have noticed during testing that there are sometimes problems with mount points disappearing and needing to be remounted, especially when we simulate certain kinds of hardware problems (as part of our testing). I would ask the Linux OS Admin to remount the file systems, if they are not mounted.

    When I have seen AIX systems with pureScale rebooted, it takes a while for the GPFS file systems to be mounted even when they do automatically get mounted. In other words, the shared file systems do not show up as soon as server comes up, and instance owner log in cannot even execute db2profile for that reason. Seems to take 3-5 minutes after reboot for GPFS shared mount points to show up.
    M. A. Feldman
    IBM Certified DBA on DB2 for Linux, UNIX, and Windows
    IBM Certified DBA on DB2 for z/OS and OS/390

  8. #8
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    The reason of the question is to simulate the situation when CF2 or CF1 experiences HW or OS fault and cannot boot. To simulate this I power off CF2 manually and try to start DB2 on CF1.

    Shared GPFS filesystems mount only when both CF1 and CF2 are online. I waited about 30 mins after CF1 boot (with CF2 offline) and shared filesystems were not mounted. As soon as I booted CF2 shared FSes mounted successfully.

  9. #9
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    Did you try to mount the file systems with db2cluster? What cluster alerts are showing?
    ---
    "It does not work" is not a valid problem statement.

  10. #10
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    I tried to mount with "mmmount -a" command of GPFS suite. FSes mounted but DB2 failed to start, I did not record the error unfortunately.

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