changing archivelog mode on 11g and 12c RAC

I hate being wrong. But it does keep happening. Last week I sat through a RAC installation (12c GI with 11gR2 database) with a client and one of the steps involved enabling archivelog mode for one of the databases. They shut down all instances, then started one of them in mount mode only.

srvctl stop database -d RAC
srvctl start instance -d RAC -i RAC1 -o mount

Just as they logged on to sqlplus and started typing “ALTER DATABASE ARCHIVELOG;” I proclaimed that this was not going to work unless they first changed CLUSTER_DATABASE in the spfile on restarted that instance. Blank looks. An enter key was pressed. To my surprise the database came back with:

SQL> ALTER DATABASE ARCHIVELOG;

Database altered.

Apparently this has changed after 10gR2 and it is not longer neccessary to fiddle with CLUSTER_DATABASE while switching archivelog mode. For years and dozens of installations I have done this extra step believing this was the way it has to be done. But not any more. I re-learned something.

3 thoughts on “changing archivelog mode on 11g and 12c RAC

  1. Thanks for the heads-up Bjoern. I’ve amended my article on that subject. The perfect crime… :)

    Cheers

    Tim…

  2. Thanks, worked like a champ.

    [oracle@myserverdb04 ~]$ sqlplus / as sysdba
    SQL> archive log list
    Database log mode No Archive Mode
    Automatic archival Disabled
    Archive destination USE_DB_RECOVERY_FILE_DEST
    Oldest online log sequence 234
    Current log sequence 236

    [oracle@myserverdb04 ~]$ srvctl stop database -d DEVDB
    [oracle@myserverdb04 ~]$ srvctl start instance -d DEVDB -i DEVDB1 -o mount
    [oracle@myserverdb04 ~]$ ps -ef |grep pmon|grep DEVDB1
    oracle 95032 1 0 14:50 ? 00:00:00 ora_pmon_DEVDB1
    [oracle@myserverdb04 ~]$ sqlplus / as sysdba
    SQL> select name from v$database;
    NAME
    ———
    DEVDB
    SQL> alter database archivelog;
    Database altered.

    SQL> archive log list;
    Database log mode Archive Mode
    Automatic archival Enabled
    Archive destination USE_DB_RECOVERY_FILE_DEST
    Oldest online log sequence 234
    Next log sequence to archive 236
    Current log sequence 236
    SQL> exit

    [oracle@myserverdb04 ~]$ srvctl stop instance -d DEVDB -i DEVDB1
    [oracle@myserverdb04 ~]$ ps -ef |grep pmon|grep DEVDB1
    [oracle@myserverdb04 ~]$ srvctl start database -d DEVDB
    [oracle@myserverdb04 ~] ps -ef |grep pmon|grep DEVDB1
    $oracle 97379 1 0 14:54 ? 00:00:00 ora_pmon_DEVDB1

    [oracle@metroodb05 ~]$ DEVDBdb
    [oracle@metroodb05 ~]$ sqlplus / as sysdba
    SQL> select name from v$database;
    NAME
    ———
    DEVDB

    SQL> archive log list
    Database log mode Archive Mode
    Automatic archival Enabled
    Archive destination USE_DB_RECOVERY_FILE_DEST
    Oldest online log sequence 233
    Next log sequence to archive 235
    Current log sequence 235

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