Thursday, March 14, 2024

ExaCC: Disable Oracle Archivelog Automatic Deletion Job

 

- Problem:

  • Some of my (ExaCC) customers reported that Oracle archive logs are automatically deleted for some databases running on ExaCC cluster, even they haven't deleted or not configured a job to backup and delete archive logs.  

- Overview:

  • Whenever we create a database on ExaCC cluster from OCI console, Oracle will add a crontab job  in VM cluster nodes to auto delete archive logs every 30 minutes.
  • Oracle uses "bkup_api" tool to auto delete archive logs.

- Checking:

   - As root user run below command to get the contents of "bkup_api" config file for your database.
     /var/opt/oracle/bkup_api/bkup_api get config --file=/<output_file> --dbname=<DB_NAME>










   - Search output config file for parameter "bkup_archlog_cron_entry". If the value is "yes", then this confirms that there is a scheduled job to automatic cleanup of archive logs.

  $ cat /tmp/exadb_bkp.conf | grep bkup_archlog_cron_entry
bkup_archlog_cron_entry=yes

    - As root user search "/etc/crontab" file for a cleanup entry specific to your database.

$ cat /etc/crontab_dba_bkp | grep exadb
19,49 * * * * oracle /var/opt/oracle/bkup_api/bkup_api bkup_archlogs --cron --dbname=exadb

     As you can see above, there is a crontab job that cleanup archive logs for database exadb every 30 minutes. 

- Solution:

- The recommended solution is configuring archive log deletion policy in RMAN repository.
For example,
CONFIGURE ARCHIVELOG DELETION POLICY TO BACKED UP 1 TIMES TO DEVICE TYPE DISK;
CONFIGURE ARCHIVELOG DELETION POLICY TO BACKED UP 1 TIMES TO DEVICE TYPE 'SBT_TAPE';

- A workaround solution, which is not recommended:
 
1. As a root user, take a backup of "/etc/crontab" file on ExaCC VM 1st node.
2. As a root user, edit file "/etc/crontab" and remove entry related to archive maintenance for each database.

In our example, remove below line.
19,49 * * * * oracle /var/opt/oracle/bkup_api/bkup_api bkup_archlogs --cron --dbname=exadb

NOTE:  You need to remove line completely from crontab, commenting out may not work in ExaCC.

3. Check "/etc/crontab" file on other DB nodes also and make sure there are no entries for archive maintenance.




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