Before you modify the database-logging mode, read Changing the Database-Logging Mode.
You add logging to a database with ontape at the same time that you create a level-0 backup.
For example, to add buffered logging to a database called stores_demo with ontape, execute the following command:
ontape -s -B stores_demo
To add unbuffered logging to a database called stores_demo with ontape, execute the following command:
ontape -s -U stores_demo
In addition to turning on transaction logging, these commands create full-system storage-space backups. When ontape prompts you for a backup level, specify a level-0 backup.