ORA-00206: Error in Writing Control File – Causes, Fixes & Prevention
ORA-00206 is a critical Oracle database error that occurs when the database fails to write to one or more control files during normal operation. The control file is the most vital binary file in an Oracle database, storing the physical structure metadata including datafile locations, redo log file locations, checkpoint information, and SCN history. Because Oracle continuously updates the control file during database activity, any write failure immediately triggers this error and can lead to a database crash.
Top 3 Causes
1. Disk Space Exhaustion
The most common cause is the filesystem or ASM disk group running out of free space where the control file resides. Oracle's checkpoint process (CKPT) and other background processes continuously write to the control file, so the moment available space is gone, writes fail instantly.
