redhat安装mysql5.5（.rpm）

安装的版本：
MySQL-server-5.5.32-2.linux2.6.i386.rpm
MySQL-client-5.5.32-2.linux2.6.i386.rpm

//卸载与安装前先查看已安装的包
# rpm -qa | grep -i mysql
MySQL-server-5.0.22-0.i386
MySQL-client-5.0.22-0.i386

//卸载
# rpm -ev MySQL-server-5.0.22-0.i386
# rpm -ev MySQL-client-5.0.22-0.i386

//安装
# rpm -ivh MySQL-server-5.5.32-2.linux2.6.i386.rpm
# rpm -ivh MySQL-client-5.5.32-2.linux2.6.i386.rpm
//如若安装不了，选择强制安装
# rpm -ivh --force MySQL-server-5.5.32-2.linux2.6.i386.rpm
# rpm -ivh --force MySQL-client-5.5.32-2.linux2.6.i386.rpm

//拷贝my-medium.cnf配置文件并修改为my.cnf
# cp /usr/share/mysql/my-medium.cnf /etc/my.cnf

//启动
# service mysql start

问题一：进入mysql工具时，总是有错误提示:
# mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)
或者
# mysql -u root -p password 'newpassword'
Enter password:
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: YES)'

解决办法，如下：
# /etc/init.d/mysql stop
# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
# mysql -u root mysql
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root'

and host='root' or host='localhost';//把空的用户密码都修改成非空的密码就行了。
mysql> FLUSH PRIVILEGES;
mysql> quit

# /etc/init.d/mysql restart
# mysql -uroot -p
Enter password: <输入新设的密码newpassword>

这样就进去mysql了

问题二：在上面mysql里面一刷新权限，结果报错，说mysql.servers表不存在
mysql> flush privileges;
ERROR 1146 (42S02): Table 'mysql.servers' doesn't exist

解决办法：
既然不存在那就创建一个，当然要先use mysql 才行，不然直接创建会报错。
mysql> USE mysql;

mysql> CREATE TABLE `servers` (
   -> `Server_name` CHAR(64) NOT NULL,
   -> `Host` CHAR(64) NOT NULL,
   -> `Db` CHAR(64) NOT NULL,
   -> `Username` CHAR(64) NOT NULL,
   -> `Password` CHAR(64) NOT NULL,
   -> `Port` INT(4) DEFAULT NULL,
   -> `Socket` CHAR(64) DEFAULT NULL,
   -> `Wrapper` CHAR(64) NOT NULL,
   -> `Owner` CHAR(64) NOT NULL,
   -> PRIMARY KEY (`Server_name`)
   -> ) ENGINE=MyISAM DEFAULT CHARSET=utf8 COMMENT='MySQL Foreign Servers

table';
Query OK, 0 rows affected (0.01 sec)
这样，问题就解决了
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)

问题三：mysql 启动错误-server PID file could not be found
ERROR! MySQL server PID file could not be found!
解决办法：
首先查看一下进程 # ps aux |grep mysq*
root      1632  0.0  0.0   5128  1408 ?        S    Jul15   0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --pid-file=/var/lib/mysql/localhost.localdomain.pid
mysql     1755  0.0  1.0 322092 34400 ?        Sl   Jul15   1:08 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib/mysql/plugin --
user=mysql --log-error=/var/lib/mysql/localhost.localdomain.err --pid-
file=/var/lib/mysql/localhost.localdomain.pid
root     11853  0.0  0.0   6908  1460 pts/3    T    01:22   0:00 /bin/sh /sbin/service mysql restart
root     11858  0.0  0.0   3044  1188 pts/3    T    01:22   0:00 /bin/sh /etc/init.d/mysql restart
root     11870  0.0  0.0   3048  1224 pts/3    T    01:22   0:00 /bin/sh /etc/init.d/mysql start
root     11876  0.0  0.0   3048  1276 pts/3    T    01:22   0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --pid-file=/var/lib/mysql/localhost.localdomain.pid
mysql    11967  0.0  0.0      0     0 pts/3    Z    01:22   0:00 [mysqld] <defunct>
root     12093  0.0  0.0   6680  1180 pts/3    T    01:23   0:00 /bin/sh /etc/init.d/mysql restart
root     12105  0.0  0.0   6684  1212 pts/3    T    01:23   0:00 /bin/sh /etc/init.d/mysql start
root     12111  0.0  0.0   6684  1276 pts/3    T    01:23   0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --pid-file=/var/lib/mysql/localhost.localdomain.pid
mysql    12202  0.0  0.0      0     0 pts/3    Z    01:23   0:00 [mysqld] <defunct>
root     12317  0.0  0.0   6680  1180 pts/3    T    01:24   0:00 /bin/sh /etc/init.d/mysql restart
root     12329  0.0  0.0   6684  1212 pts/3    T    01:24   0:00 /bin/sh /etc/init.d/mysql start
root     12335  0.0  0.0   6684  1272 pts/3    T    01:24   0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --pid-file=/var/lib/mysql/localhost.localdomain.pid
mysql    12600  0.0  0.0      0     0 pts/3    Z    01:24   0:00 [mysqld] <defunct>
root     12622  0.0  0.0   6908  1464 pts/3    T    01:24   0:00 /bin/sh /sbin/service mysql restart
root     12627  0.0  0.0   3044  1192 pts/3    T    01:24   0:00 /bin/sh /etc/init.d/mysql restart
root     12639  0.0  0.0   3048  1224 pts/3    T    01:24   0:00 /bin/sh /etc/init.d/mysql start
root     12645  0.0  0.0   3048  1276 pts/3    T    01:24   0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --pid-file=/var/lib/mysql/localhost.localdomain.pid
mysql    12910  0.0  0.0      0     0 pts/3    Z    01:24   0:00 [mysqld] <defunct>
root     13561  0.0  0.0   6684  1212 pts/3    T    01:33   0:00 /bin/sh /etc/init.d/mysql start
root     13567  0.0  0.0   6684  1368 pts/3    T    01:33   0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --pid-file=/var/lib/mysql/localhost.localdomain.pid
mysql    13832  0.0  0.0      0     0 pts/3    Z    01:33   0:00 [mysqld] <defunct>
root     13953  0.0  0.0   6684  1216 pts/3    T    01:34   0:00 /bin/sh /etc/init.d/mysql start
root     13959  0.0  0.0   6684  1272 pts/3    T    01:34   0:00 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --pid-file=/var/lib/mysql/localhost.localdomain.pid
mysql    14224  0.0  0.0      0     0 pts/3    Z    01:34   0:00 [mysqld] <defunct>
root     14380  0.0  0.0   5984   764 pts/3    S+   01:50   0:00 grep mysq*

如果看到上面的内容，那说明，Mysql的进程卡死了，这时用就要把这些卡死的进程都关闭
[root@localhost ~]# kill 1632
[root@localhost ~]# kill 1755
启动Mysql就ok了
# service mysql start
Starting MySQL.                                            [  OK  ]