If a media failure happens, check if the media failure is permanent or temporary.
If the media failure is temporary, simply have the hardware problem fixed
If the media failure is permanent, check if the database is open. If not, mount the database.
Check if the damaged online redo log is archived . If not issue the ALTER DATABASE CLEAR UNARCHIVED LOGFILE <group_number); command
If the damaged online redo log is archived, use the ALTER DATABASE CLEAR LOGFILE <group_number>; command