Oracle® Database 11g / 12c / 18c error codes ORA-00204: error in reading (block [string], # blocks [string]) of control file

ORA-00204: error in reading (block [string], # blocks [string]) of control file

Oracle Error Code: ORA-00204

Cause: A disk I/O failure was detected on reading the control file.

Action: Check if the disk is online, if it is not, bring it online and try a warm start again. If it is online, then you need to recover the disk.