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
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| 123 | [root@serv01 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
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| 1 | [root@serv01 databackup]# yum install perl* -y |
第三步，对数据库larrydb热拷贝
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| 1 | [root@serv01 databackup]# mysqlhotcopy --help |
#第一种写法
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| 1 | [root@serv01 databackup]# mysqlhotcopy --user=root --password=123456 larrydb /databackup/ |
#第二种写法
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| 12345678 | [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
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[root@serv01 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.MYI mysql> 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 specified mysql> 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[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
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[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 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[root@serv01 databackup]# mysql -uroot -p123456 < larrydb.sql mysql> 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！