Innodb_log_file_size InnoDB cannot be enabled

After innodb_log_file_size is modified, InnoDB cannot be enabled. When/etc/init. d/mysqld restart is restarted, no error is prompted. When I use mysql> show engines;, InnoDB does not exist and I sweat. Check the log./var/log/mysqld. Log found an error. As follows:

 

111231 04:59:17 mysqld_safe mysqld from PID file/var/run/mysqld. PID end
111231 04:59:18 mysqld_safe starting mysqld daemon with databases from/var/lib/MySQL
InnoDB: Error: Log File./ib_logfile0 is of different size 0 5242880 bytes
InnoDB: than specified in the. CNF file 0 268435456 bytes!
111231 4:59:18 [Error] plugin 'innodb' init function returned error.
111231 4:59:18 [Error] plugin 'innodb' registry as a storage engine failed.

[Root @ localhost MySQL] # rm-F ib_logfile *

it's okay to restart mysql. I think if innodb_log_file_size is modified, files such as ib_logfile should be automatically converted to the configured size. If they cannot be automatically converted to the configured size, a prompt should also be prompted when you restart MySQL.