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---- mysql mysql 17G 10月 : ibdata1
-rw-rw---- mysql mysql 5.0M 10月 : ib_logfile0
-rw-rw---- mysql mysql 5.0M 10月 : ib_logfile1
drwx------ mysql mysql .0K 2月 mysql
srwxrwxrwx mysql mysql 10月 : mysql.sock
drwx------ mysql mysql .0K 2月 test
drwx------ mysql mysql .0K 2月 zabbix # mkdir /usr2/mysql
# chown mysql:mysql /usr2/mysql # su - mysql
$id
uid=(mysql) gid=(mysql) 组=(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= [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= [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 ) 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 (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
Server version: 5.1. Source distribution Copyright (c) , , Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| test |
| zabbix |
+--------------------+
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 |
……