一次原始碼新裝的mysql,由於沒有複製my-default.cnf到/etc/my.cnf位置，在啟動mysql的時候碰到了無法開啟mysql.user表的錯誤。具體錯誤為：[ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.user' doesn't exist。下面是該錯誤的描述及其解決辦法。

1、現象描述
[[email protected] scripts]# service mysqld start
Starting MySQL..The server quit without updating PID file (/var/lib/mysql/HKBO.pid).[FAILED]

#檢視錯誤日誌
[[email protected] scripts]# tail /var/log/mysqld.log
InnoDB: Apply batch completed
2014-12-08 11:01:37 15721 [Note] InnoDB: 128 rollback segment(s) are active.
2014-12-08 11:01:37 15721 [Note] InnoDB: Waiting for purge to start
2014-12-08 11:01:37 15721 [Note] InnoDB: 5.6.12 started; log sequence number 1600607
2014-12-08 11:01:37 15721 [Note] Server hostname (bind-address): '*'; port: 3306
2014-12-08 11:01:37 15721 [Note] IPv6 is available.
2014-12-08 11:01:37 15721 [Note]   - '::' resolves to '::';
2014-12-08 11:01:37 15721 [Note] Server socket created on IP: '::'.
2014-12-08 11:01:37 15721 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.user' doesn't exist
141208 11:01:37 mysqld_safe mysqld from pid file /var/lib/mysql/HKBO.pid ended

2、解決辦法
#檢視當前的my.cnf配置檔案
[[email protected] scripts]# more /etc/my.cnf |grep -v ^#
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
old_passwords=1

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

#由於編譯安裝時指定的路徑為/opt/data以及mysql_install_db時指定的datadir也為/opt/data,而my.cnf為預設的路徑
#因此修改datadir至正確路徑後，問題解決
[

[[email protected] support-files]# service mysqld start
Starting MySQL.[  OK  ]