On-line/Off-line Backup (OS)
You can back up your database using Operating System (OS) commands along with Oracle system views. Although OS backups allow database recovery, the recovery process may be more complex than using RMAN. We recommend OS backups as an interim backup strategy until RMAN is in place.
A cold backup is a backup performed when the database is completely shut down. A hot backup is one performed when the database is open and possibly in use. An Instance is a synonym for an Oracle database.
Off-line backups, or cold backups, require database shutdown before making a backup. Restored cold backups resolve any kind of database failure, as long as the backed up files are intact.
On-line backups, or hot backups, do not require database shutdown. Active transactions can be running while the backup occurs. On-line backups can recover from many failures, but some types of failures may require restoring to an off-line backup and then recovering from there. See the Oracle manuals for instructions about how to do hot and cold backups.