MySQL备份与恢复之热拷贝(4)

来源:转载


       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

[[email protected] databackup]# mysqlhotcopy -uroot -p123456 --database larrydb > larrydb_hostcopy.sqlCan'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

[[email protected] databackup]# yum install perl* -y

第三步,对数据库larrydb热拷贝

[[email protected] databackup]# mysqlhotcopy --help

#第一种写法

[[email protected] databackup]# mysqlhotcopy --user=root --password=123456 larrydb /databackup/

#第二种写法

[[email protected] 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

[[email protected] databackup]# ll larrydbtotal 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.MYImysql> use larrydb;Database changedmysql> show tables;+-------------------+| Tables_in_larrydb |+-------------------+| class || stu |+-------------------+2 rows in set (0.00 sec)mysql> show create table class /G;*************************** 1. row *************************** Table: classCreate Table: CREATE TABLE `class` ( `cid` int(11) DEFAULT NULL, `cname` varchar(30) DEFAULT NULL) ENGINE=InnoDB DEFAULT CHARSET=latin11 row in set (0.00 sec)ERROR: No query specifiedmysql> show create table stu /G;*************************** 1. row *************************** Table: stuCreate Table: CREATE TABLE `stu` ( `sid` int(11) DEFAULT NULL, `sname` varchar(30) DEFAULT NULL, `cid` int(11) DEFAULT NULL) ENGINE=MyISAM DEFAULT CHARSET=latin11 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[[email protected] databackup]# rm -rf /usr/local/mysql/data/larrydb/*[[email protected] databackup]# rm -rf /usr/local/mysql/data/larrydb/

 
第五步,恢复数据

[[email protected] 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 changedmysql> 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 existmysql> 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[[email protected] databackup]# mysql -uroot -p123456 < larrydb.sqlmysql> use larrydb;Database changedmysql> 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!



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