After upgrading MySQL on CentOS, there is a problem that the service cannot be started. After running Mysqld_safe, look at the log information and see the error shown in the title.
Search later found that the configuration is not correct, is not the two version of the configuration is not compatible with each other? So it's called upgrading? Hang Daddy!
version: MySQL5.5.8 GA
Symptom: Unable to start MySQL, error in "MySQL database directory/hostname. err" log file unknown/unsupported storage Engine:innodb
Reason: The MySQL5.5.8 GA default engine is InnoDB, and the configuration file (MY.CNF) is set in Skip-innodb
Workaround: set Default-storage-engine=myisam in the configuration file (MY.CNF)
What if the default engine wants to use InnoDB?
Comment out the Skip-innodb and configure the InnoDB parameter correctly
[ERROR] unknown/unsupported Storage Engine:innodb