MySQL ibdata1文件迁移

目的：主机系统/var目录快满了，经查询最大的文件是mysql的ibdata1文件，有17G大小，故需要迁移这个文件到其他目录下，以释放/var目录空间。

1.先备份下数据库是个好习惯

# mysqldump -q -uuser -ppassword --add-drop-table --all-databases > /usr2/backup/mysql_1013.sql

2.关闭mysql服务

# /etc/init.d/mysqld stop

停止 mysqld： [确定]

# /etc/init.d/mysqld status

mysqld 已停

3.移动ibdata1及其同目录下的文件，从/var/lib/mysql移动到/usr2/mysql

# pwd

/var/lib/mysql

# ls -lh

总用量 17G

-rw-rw---- 1 mysql mysql  17G 10月 13 10:23 ibdata1

-rw-rw---- 1 mysql mysql 5.0M 10月 13 10:23 ib_logfile0

-rw-rw---- 1 mysql mysql 5.0M 10月 13 10:23 ib_logfile1

drwx------ 2 mysql mysql 4.0K 2月  19 2014 mysql

srwxrwxrwx 1 mysql mysql    0 10月 13 10:23 mysql.sock

drwx------ 2 mysql mysql 4.0K 2月  19 2014 test

drwx------ 2 mysql mysql 4.0K 2月  26 2014 zabbix



# mkdir /usr2/mysql

# chown mysql:mysql /usr2/mysql



# su - mysql

$id

uid=27(mysql) gid=27(mysql) 组=27(mysql)

$ mv /var/lib/mysql/* /usr2/mysql/

$

4.修改mysql配置文件/etc/my.cnf,修改datadir和socket路径指向

修改前：

# more /etc/my.cnf

[mysqld]

datadir=/var/lib/mysql

socket=/var/lib/mysql/mysql.sock

user=mysql

# Disabling symbolic-links is recommended to prevent assorted security risks

symbolic-links=0



[mysqld_safe]

log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid



修改后：

# more /etc/my.cnf

[mysqld]

datadir=/usr2/mysql

socket=/usr2/mysql/mysql.sock

user=mysql

# Disabling symbolic-links is recommended to prevent assorted security risks

symbolic-links=0



[mysqld_safe]

log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid

5.启动mysql服务

# /etc/init.d/mysqld start

正在启动 mysqld： [确定]

# /etc/init.d/mysqld status

mysqld (pid  11907) 正在运行...

6.连接mysql，根据报错提示创建mysql.sock的软连接，验证库表数据，完成迁移工作。

# mysql -uuser -ppassword

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)



# ln -s /usr2/mysql/mysql.sock /var/lib/mysql/mysql.sock



# mysql -uuser -ppassword

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 21

Server version: 5.1.66 Source distribution



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mysql> show databases;

+--------------------+

| Database           |

+--------------------+

| information_schema |

| test               |

| zabbix             |

+--------------------+

3 rows in set (0.00 sec)



mysql> use zabbix

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A



Database changed

mysql> show tables;

+-----------------------+

| Tables_in_zabbix      |

+-----------------------+

| acknowledges          |

| actions               |

| alerts                |

……