I’ve upgraded MySQL 5.0 to MySQL 5.5 with MySQL databases. When I start MySQL the service could not be started. I checked the Mysql error logs, saw below errors:
InnoDB: Error: log file ./ib_logfile2 is of different size 0 0 bytes InnoDB: than specified in the .cnf file 0 268435456 bytes! 120702 11:44:05 [ERROR] Plugin 'InnoDB' init function returned error. 120702 11:44:05 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. 120702 11:44:05 [ERROR] Unknown/unsupported storage engine: InnoDB 120702 11:44:05 [ERROR] Aborting
For solution, I remove the ib_logfile files and start MySQL again. Now this time, it is working fine.
[root@mysql]# rm -f ib_logfile*