Backup and Restore Limitations in File-Based Mode

Some of the backup and restore limitations include:

The online redo logs are exclusively locked by Oracle while the Oracle server is online. Perform an offline backup, if necessary.
To restore either the system tablespace or a tablespace containing rollback segments, you must first shut down the database and perform a full database restore.
The Agent for Oracle in File-based mode can back up only those parameter files that are located under the default location (ORACLE_HOME\dbs and ORACLE_HOME\database).
The Agent for Oracle in File-based mode does not support backup and restore processes on raw devices and Automatic Storage Management (ASM).
You must grant access permissions to the Backup Operators group to backup Oracle data files before using this role to perform the backup and restore operations.

More information: