1. Execute start and report an error:
# /etc/init.d/mysqld start MySQL Daemon failed to start. Starting mysqld: [FAILED]
2. View the log file of mysqld
#tail -n 100 /var/log/mysqld.log
[ERROR] InnoDB: The Auto-extending innodb_system data file './ibdata1' is of a different size 640 pages (rounded down to MB) than specified in the .cnf file: initial 768 pages, max 0 (relevant if non-zero) pages! [ERROR] InnoDB: Plugin initialization aborted with error Generic error [ERROR] Plugin 'InnoDB' init function returned error. [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed. [ERROR] Failed to initialize plugins. [ERROR] Aborting
3. Solution:
Since it is the first installation and an error is reported, delete all the files in the /var/lib/mysql directory directly, and then restart it successfully.