一 使用percona-xtrabackup的原因

 

在前面，我们讲到MySQL冷备、热备、mysqldump、热拷贝、保证数据的一致性。因为mysql冷备、mysqldump、mysql热拷贝均不能实现增量备份，在实际环境中增量备份是使用较多的，percona-xtrabackup就是为实现增量备份而生，因此我们需要使用percona-xtrabackup。

 

本文讲解percona-xtrabackup软件的使用，下一篇文章讲解percona-xtrabackup实现增量备份及恢复。

 

二 什么是percona-xtrabackup

 

Percona XtraBackup is an open-source hot backup utility for MySQL -based servers that doesn’t lock your database during the backup.

 

It can back up data from InnoDB, XtraDB,and MyISAM tableson MySQL 5.1 [1], 5.5 and5.6 servers, as well as Percona Server with XtraDB.For a high-level overview of many of its advanced features, including a featurecomparison, please see AboutPercona Xtrabackup.

 

Whether it is a 24x7 highly loaded server or alow-transaction-volume environment, Percona XtraBackup isdesigned to make backups a seamless procedure without disrupting theperformance of the server in a production environment.Commercial support contracts areavailable.

 

Percona XtraBackup is a combination of the xtrabackup C program,and the innobackupex Perl script. The xtrabackupprogramcopies and manipulates InnoDB and XtraDB datafiles, and the Perl script enables enhanced functionality,such as interacting with a running MySQL server and backing up MyISAM tables.

 

 

三 软件及文档获取

 

软件获取

http://www.percona.com/software/percona-xtrabackup/downloads

http://download.csdn.net/detail/wentasy/6638171

 

文档获取

http://www.percona.com/doc/percona-xtrabackup/2.1/

http://download.csdn.net/detail/wentasy/6638029

 

四 软件使用讲解

 

注：本文采用的percona-xtrabackup版本为2.0.2，操作系统版本为RHEL 6.1 Server，MySQL版本为5.1

第一步，准备文件并拷贝文件

[root@larrywen ule-mysql]# ll percona-xtrabackup-2.0.2-461.rhel6.x86_64.rpm 
-rwxr-xr-x. 1 root root 3786628 Sep 10 13:45 percona-xtrabackup-2.0.2-461.rhel6.x86_64.rpm

[root@larrywen ule-mysql]# scp percona-xtrabackup-2.0.2-461.rhel6.x86_64.rpm 192.168.1.11:/opt

 

第二步，该软件需要依赖MySQL客户端，所以使用yum安装。注意，此处安装的只是MySQL的客户端，和本身使用源码安装的MySQL不冲突

[root@serv01 opt]# yum install percona-xtrabackup-2.0.2-461.rhel6.x86_64.rpm -y
Installed:
  percona-xtrabackup.x86_64 0:2.0.2-461.rhel6                                                                                         

Dependency Installed:
  mysql.x86_64 0:5.1.52-1.el6_0.1

 

第三步，初始化备份

[root@serv01 databackup]# innobackupex --user=root --password=123456 /databackup/
InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2012.  All Rights Reserved.

……
innobackupex: Backup created in directory '/databackup/2013-09-10_21-49-44'
innobackupex: MySQL binlog position: filename 'mysql-bin.000001', position 7312
130910 21:50:03  innobackupex: completed OK!

 

第四步，这样的备份文件无法使用，我们需要做统一检查

[root@serv01 databackup]# ll
total 4
drwxr-xr-x. 9 root root 4096 Sep 10 21:50 2013-09-10_21-49-44

#做统一检查
[root@serv01 databackup]# innobackupex --apply-log /databackup/2013-09-10_21-49-44/

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2012.  All Rights Reserved.
……
xtrabackup: starting shutdown with innodb_fast_shutdown = 1
130910 21:51:52  InnoDB: Starting shutdown...
130910 21:51:56  InnoDB: Shutdown completed; log sequence number 2098188
130910 21:51:56  innobackupex: completed OK!

 

第五步，模拟数据丢失

[root@serv01 databackup]# rm -rf /usr/local/mysql/data/*
[root@serv01 databackup]# ll /usr/local/mysql/data/
total 0

第六步，恢复数据

[root@serv01 databackup]# innobackupex --copy-back /databackup/2013-09-10_21-49-44/

InnoDB Backup Utility v1.5.1-xtrabackup; Copyright 2003, 2009 Innobase Oy
and Percona Inc 2009-2012.  All Rights Reserved.
……
innobackupex: Starting to copy InnoDB system tablespace
innobackupex: in '/databackup/2013-09-10_21-49-44'
innobackupex: back to original InnoDB data directory '/usr/local/mysql/data'
innobackupex: Copying file '/databackup/2013-09-10_21-49-44/ibdata1'

innobackupex: Starting to copy InnoDB log files
innobackupex: in '/databackup/2013-09-10_21-49-44'
innobackupex: back to original InnoDB log directory '/usr/local/mysql/data'
innobackupex: Finished copying back files.

130910 22:02:29  innobackupex: completed OK!

 

第七步，重启mysql服务，发现报错，pkill掉，然后启动一切正常

[root@serv01 databackup]# /etc/init.d/mysqld restart
 ERROR! MySQL server PID file could not be found!
Starting MySQL. ERROR! The server quit without updating PID file (/usr/local/mysql/data/serv01.host.com.pid).

#查看恢复的数据目录，拥有者和所属组不是mysql用户，我们更改拥有者和所属组
[root@serv01 databackup]# ll /usr/local/mysql/data/
total 18468
drwxr-xr-x. 2 root  root      4096 Sep 10 22:02 game
drwxr-xr-x. 2 root  root      4096 Sep 10 22:02 hello
-rw-r-----. 1 root  root  18874368 Sep 10 21:51 ibdata1
drwxr-xr-x. 2 root  root      4096 Sep 10 22:02 larrydb
drwxr-xr-x. 2 root  root      4096 Sep 10 22:02 mnt
drwxr-xr-x. 2 root  root      4096 Sep 10 22:02 mysql
-rw-rw----. 1 mysql mysql        0 Sep 10 22:02 mysql-bin.index
drwxr-xr-x. 2 root  root      4096 Sep 10 22:02 performance_schema
-rw-r-----. 1 mysql root       771 Sep 10 22:02 serv01.host.com.err
drwxr-xr-x. 2 root  root      4096 Sep 10 22:02 test
-rw-r--r--. 1 root  root        24 Sep 10 22:02 xtrabackup_binlog_pos_innodb

[root@serv01 databackup]# chown mysql.mysql /usr/local/mysql/data/ -R

#再次启动，仍然失败，我们杀掉进程，再次启动mysql，正常
[root@serv01 databackup]# /etc/init.d/mysqld restart
 ERROR! MySQL server PID file could not be found!
Starting MySQL.. ERROR! The server quit without updating PID file (/usr/local/mysql/data/serv01.host.com.pid).

[root@serv01 databackup]# ps -ef | grep mysql
root      2386     1  0 18:36 pts/0    00:00:00 /bin/sh /usr/local/mysql/bin/mysqld_safe --datadir=/usr/local/mysql/data --pid-file=/usr/local/mysql/data/serv01.host.com.pid
mysql     2664  2386  0 18:36 pts/0    00:00:00 /usr/local/mysql/bin/mysqld --basedir=/usr/local/mysql --datadir=/usr/local/mysql/data --plugin-dir=/usr/local/mysql/lib/plugin --user=mysql --log-error=/usr/local/mysql/data/serv01.host.com.err --pid-file=/usr/local/mysql/data/serv01.host.com.pid --socket=/tmp/mysql.sock --port=3306
root      3022  1490  0 19:39 pts/0    00:00:00 mysql -uroot -px xxxx
root      5021  3040  0 22:05 pts/2    00:00:00 grep mysql
[root@serv01 databackup]# pkill -9 mysql
[root@serv01 databackup]# /etc/init.d/mysqld start
Starting MySQL.. SUCCESS! 

[root@serv01 databackup]# mysql -uroot -p123456 
Server version: 5.5.29-log Source distribution
mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| game               |
| hello              |
| larrydb            |
| mnt                |
| mysql              |
| performance_schema |
| test               |
+--------------------+
8 rows in set (0.00 sec)

 

五 参考资料

http://www.percona.com/doc/percona-xtrabackup/2.1/

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  2013年12月1日
  By Larry Wen