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MySQL备份与恢复之热拷贝(4)

2015-08-12 00:00 本站整理 浏览(262)

在上一篇文章中我们提到热备,热备也就是在MySQL或者其他数据库服务在运行的情况下进行备份。本文分享另外一种备份的方法,也就是热拷贝。热拷贝跟热备很类似,只不过热备使用mysqldump命令,热拷贝使用mysqlhotcopy命令。热拷贝的优势在于支持服务运行中进行备份,速度快,性能好;劣势在于只能备份MyIsam的表,无法备份InnoDB的表。所以在生产环境中应该酌情使用。

示意图

热备模拟第一步,热拷贝

[root@serv01 databackup]# mysqlhotcopy -uroot -p123456 --database larrydb > larrydb_hostcopy.sql

Can't locate DBI.pm in @INC (@INC contains: /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at /usr/local/mysql/bin/mysqlhotcopy line 25.

BEGIN failed--compilation aborted at /usr/local/mysql/bin/mysqlhotcopy line 25.

第二步,报错。因为这个命令是用perl写的或者此命令需要perl支持,所以需要安装perl

[root@serv01 databackup]# yum install perl* -y

第三步,对数据库larrydb热拷贝

[root@serv01 databackup]# mysqlhotcopy --help

#第一种写法

[root@serv01 databackup]# mysqlhotcopy --user=root --password=123456 larrydb /databackup/

#第二种写法

[root@serv01 databackup]# mysqlhotcopy -u root -p 123456 larrydb /databackup/

Flushed 2 tables with read lock (`larrydb`.`class`, `larrydb`.`stu`) in 0 seconds.

Locked 0 views () in 0 seconds.

Copying 5 files...

Copying indices for 0 files...

Unlocked tables.

mysqlhotcopy copied 2 tables (5 files) in 0 seconds (0 seconds overall).

第四步,模拟数据丢失

[root@serv01 databackup]# ll larrydb

total 36

-rw-rw----. 1 mysql mysql 8590 Sep 10 19:07 class.frm

-rw-rw----. 1 mysql mysql 65 Sep 10 19:07 db.opt

-rw-rw----. 1 mysql mysql 8618 Sep 10 19:07 stu.frm

-rw-rw----. 1 mysql mysql 48 Sep 10 19:07 stu.MYD

-rw-rw----. 1 mysql mysql 1024 Sep 10 19:07 stu.MYI

mysql> use larrydb;

Database changed

mysql> show tables;

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

| Tables_in_larrydb |

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

| class |

| stu |

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

2 rows in set (0.00 sec)

mysql> show create table class \G;

*************************** 1. row ***************************

Table: class

Create Table: CREATE TABLE `class` (

`cid` int(11) DEFAULT NULL,

`cname` varchar(30) DEFAULT NULL

) ENGINE=InnoDB DEFAULT CHARSET=latin1

1 row in set (0.00 sec)

ERROR:

No query specified

mysql> show create table stu \G;

*************************** 1. row ***************************

Table: stu

Create Table: CREATE TABLE `stu` (

`sid` int(11) DEFAULT NULL,

`sname` varchar(30) DEFAULT NULL,

`cid` int(11) DEFAULT NULL

) ENGINE=MyISAM DEFAULT CHARSET=latin1

1 row in set (0.00 sec)

ERROR:

mysql> drop table class,stu;

Query OK, 0 rows affected (0.01 sec)

mysql> show tables;

Empty set (0.00 sec)

#这样删除会出错,不要这样删除

[root@serv01 databackup]# rm -rf /usr/local/mysql/data/larrydb/*

[root@serv01 databackup]# rm -rf /usr/local/mysql/data/larrydb/

第五步,恢复数据

[root@serv01 databackup]# cp larrydb /usr/local/mysql/data/ -arvf

`larrydb' -> `/usr/local/mysql/data/larrydb'

`larrydb/stu.MYI' -> `/usr/local/mysql/data/larrydb/stu.MYI'

`larrydb/stu.MYD' -> `/usr/local/mysql/data/larrydb/stu.MYD'

`larrydb/stu.frm' -> `/usr/local/mysql/data/larrydb/stu.frm'

`larrydb/db.opt' -> `/usr/local/mysql/data/larrydb/db.opt'

`larrydb/class.frm' -> `/usr/local/mysql/data/larrydb/class.frm'

mysql> use larrydb;

Database changed

mysql> show tables;

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

| Tables_in_larrydb |

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

| class |

| stu |

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

2 rows in set (0.00 sec)

mysql> select * from class;

ERROR 1146 (42S02): Table 'larrydb.class' doesn't exist

mysql> select * from stu;

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

| sid | sname | cid |

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

| 1 | larry01 | 1 |

| 2 | larry02 | 2 |

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

2 rows in set (0.00 sec)

mysql> drop database larrydb;

Query OK, 2 rows affected (0.00 sec)

#再次导入

[root@serv01 databackup]# mysql -uroot -p123456 < larrydb.sql

mysql> use larrydb;

Database changed

mysql> show tables;

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

| Tables_in_larrydb |

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

| class |

| stu |

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

2 rows in set (0.00 sec)

mysql> select * from stu;

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

| sid | sname | cid |

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

| 1 | larry01 | 1 |

| 2 | larry02 | 2 |

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

2 rows in set (0.00 sec)

mysql> select * from class;

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

| cid | cname |

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

| 1 | linux |

| 2 | oracle |

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

2 rows in set (0.00 sec)

本文介绍了另一种备份--热拷贝,与热备的区别在于使用的命令不同,热拷贝使用mysqlhotcopy命令,希望大家可以亲自动手操作一下!