Oracle ARCHIVELOG mode creates excess activity / excess disk usage

In an SA (Server Automation) or BSAE (Business Service Automation Essentials) installation, on reviewing the Oracle activities/performance, you notice what appears to be excessive archiving of the redo log files.

You see this as a possible sign of incorrect SA / BSAE performance and/or as a threat to excessive use of system resources, such as disk usage which might lead it to exhausting the free space on a partition.

By default, neither SA nor BSAE require ARCHIVELOG mode to be enabled for product functionality. Certainly when using the included Oracle installer for SA (or for BSAE prior to v9.10), ARCHIVELOG is not enabled.

If it was enabled, then the most likely cause for this is that your organization’s DBA has a policy which requires ARCHIVELOG mode to be enabled. Again, this is not a requirement for SA / BSAE to function correctly.

We do understand that by enabling ARCHIVELOG mode that you will quite likely see a sudden increase in Oracle DB instance activity over what it was like prior to enabling ARCHIVELOG mode. This is normal and expected. No corrective action is required, although you might want to discuss with your DBA regarding ensuring that neither the database’s performance nor the database server’s free disk space is being pushed to critical limits.

If database performance or disk space utilization is a concern, please disable ARCHIVELOG mode.

To check whether your database instance is running in ARCHIVELOG mode, please run the following commands from the Oracle user shell:

$ sqlplus ‘/ as sysdba’

SQL> select log_mode from v$database;

LOG_MODE

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