A raw device is a hard disk or part of a hard disk not managed by the operating system. On Unix and Linux systems, you can use raw devices as volumes.
Database Administration, Planning the Database
Concepts of the Database System, Volumes (Permanent Storage)
Database Studio, Adding or Deleting Data Volumes, Adding Log Volumes
Database Manager CLI, Configuring Database Instances, db_addvolume
Database Administration in CCMS, Volumes