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  1. #1
    Join Date
    Apr 2003
    Location
    Melbourne, Australia
    Posts
    53

    Unanswered: Oracle 8i Data Guard

    Hi All,

    I have implemented a managed standby database using the Oracle 8i Data Guard. The log files are archived on the primary server, they are automatically shipped to the standby server. I am able to convert the standby database as READ ONLY and then change it back to recovery mode. However, when i tried to do a switchover i got the following message

    ************************************************** ***
    DGDCTL> switchover -v
    Refer to /u01/app/oracle/product/8.1.7.4/dataguard/log/switchover_TEST.log on test1 for detailed information
    Would you like to continue?
    (Y)es or (N)o? Y
    Step 1: Started: Check Switchover Prerequisites
    Substep 1.1: Verification of host availability completed
    Substep 1.2: Verification of agent states completed
    WARNING: Detected unrecoverable file /u01/oradata/TEST/system01.dbf with unrecoverable date AUG-22-2005:12:14:52 in production
    WARNING: Detected unrecoverable file /u02/oradata/TEST/DATWH1.dbf with unrecoverable date SEP-03-2003:12:05:47 in production
    WARNING: Detected unrecoverable file /u03/oradata/TEST/IDXWH1.dbf with unrecoverable date APR-07-2008:01:56:20 in production
    Would you like to continue?
    [YES|NO or Y|N]: N
    Aborting operation.

    Substep 1.3: Check for unrecoverable changes failed
    Step 1: Check prerequisites failed
    ALERT: switchover failed

    Attempt to start agents after a switchover
    Attempt to Start Production Agent
    Starting agent will take a couple of seconds.
    Start Production Agent Completed Successfully

    Attempt to Start Standby Agent
    Mounting standby database and starting agent will take a couple of seconds.
    Start Standby Agent Completed Successfully

    ************************************************** ***

    Any ideas on why these tablespaces are unrecoverable? I created this standby database using a copy of the production database (while the database was shutdown)

    Appreciate your help

  2. #2
    Join Date
    Jun 2003
    Location
    West Palm Beach, FL
    Posts
    2,713

    Cool Logs?

    Are you applying the archive logs at the standby?
    The person who says it can't be done should not interrupt the person doing it. -- Chinese proverb

  3. #3
    Join Date
    Apr 2003
    Location
    Melbourne, Australia
    Posts
    53
    The archive logs are being applied automatically since Data Guard is implemented. I am trying to do a switchover to convert the existing production server as a secondary server and vice-versa. While doing this switchover, in the pre-requisite step, I am getting a warning saying that some of the tablespaces are unrecoverable.

    I ran an sql “select name, unrecoverable_change#, unrecoverable_time from v$datafile where unrecoverable_change# <> 0” and got the following result

    DR Server:

    NAME UNRECOVERABLE_CHANGE# UNRECOVERABLE_TIME#
    ------- ------------- -------------

    /u01/oradata/TEST/system01.dbf 1559963 22/08/2005 12:14:52

    /u02/oradata/TEST/DATWH1.dbf 332254 03/09/2003 12:05:47

    /u03/oradata/TEST/IDXWH1.dbf 6408144 07/04/2008 13:56:20


    Prod Server:

    NAME UNRECOVERABLE_CHANGE# UNRECOVERABLE_TIME#
    ------- ------------- -------------

    /u01/oradata/TEST/system01.dbf 1559963 22/08/2005 12:14:52

    /u02/oradata/TEST/DATWH1.dbf 332254 03/09/2003 12:05:47

    /u03/oradata/TEST/IDXWH1.dbf 6408144 07/04/2008 13:56:20


    The Oracle documentation says that if the unrecoverable_change# for a datafile reported (v$datafile) by the primary is greater than that reported by the standby then you will need to recover that datafile (by copying it over from the primary) in order to avoid block corruption errors if the standby is activated.

    Does this also hold if the unrecoverable_change# are identical?

    Will it have any impact if i go ahead with the switchover?

  4. #4
    Join Date
    Apr 2003
    Location
    Melbourne, Australia
    Posts
    53
    This is to let everyone know that I started the switchover, even after receiving this warning, and was successful in completing this process. So, its fine to go ahead with the switchover even though these warnings are present. I believe the reason for this is that the unrecoverable errors were generated before the standby database/Dataguard was implemented and the unrecoverable_change# were identical.

    Hope this will help others who might get caught in a similar situation.

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