Fatal error: Can’t open and lock privilege tables: Table ‘mysql.host’ doesn’t exist

My MySQL DB crashed after a Quarter Maintenance. I tried to start it

bin/mysqld_safe --user=mysql

Error:

InnoDB: Database was not shut down normally!...
Fatal error: Can't open and lock privilege tables: Table 'mysql.host' doesn't exist

Solution:

https://dev.mysql.com/doc/refman/5.1/en/binary-installation.html

https://bbs.archlinux.org/viewtopic.php?id=137365

shell> scripts/mysql_install_db --user=mysql
shell> chown -R root .
shell> chown -R mysql data
shell> bin/mysqld_safe --user=mysql &