How to Enable Archivelog Mode for an Oracle database

This is a quick post about the steps required to enable the ARCHIVELOG mode for an oracle database (Single Instance or RAC)

To check if the archive log mode is enabled or not, use the following command:

SYS@XPS 01-SEP-18 SQL> archive log list
Database log mode               No Archive Mode
Automatic archival               Disabled
Archive destination              USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence 7164
Current log sequence           7167

If the database is not in the archivelog mode , you need first to set the archiving location, using one of the following options:

alter system set log_archive_dest_1=’LOCATION=+RECO_DG’;
OR
alter system set log_archive_dest_1=’LOCATION=USE_DB_RECOVERY_FILE_DEST’;

For Single Instance Database, follow the following steps:

shutdown immediate
startup mount
alter database archivelog;
alter database open;

Now check the archivelog mode again:

SYS@XPS 01-SEP-18 SQL> archive log list;
Database log mode                    Archive Mode
Automatic archival                    Enabled
Archive destination                   USE_DB_RECOVERY_FILE_DEST
Oldest online log sequence      7164
Next log sequence to archive  7167
Current log sequence                7167

For RAC Instance Database:

srvctl stop database -d PROD
srvctl start database -d PROD -o mount
sqlplus / as sysdba
alter database archivelog;
exit;
srvctl stop database -d PROD
srvctl start database -d PROD

That is all.

Thanks
Ahmed