一 使用percona-xtrabackup的原因
在前面，我們講到MySQL冷備、熱備、mysqldump、熱拷貝、保證數據的一致性。因為mysql冷備、mysqldump、mysql熱拷貝均不能實現增量備份，在實際環境中增量備份是使用較多的，percona-xtrabackup就是為實現增量備份而生，因此我們需要使用percona-xtrabackup。
本文講解percona-xtrabackup軟件的使用，下一篇文章講解percona-xtrabackup實現增量備份及恢復。
二 什麼是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 About Percona 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 xtrabackup programcopies 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 軟件及文檔獲取
軟件獲取
percona-xtrabackup
percona-xtrabackup
文檔獲取
percona-xtrabackup
percona-xtrabackup
四 軟件使用講解
注：本文采用的percona-xtrabackup版本為2.0.2，操作系統版本為RHEL 6.1 Server，MySQL版本為5.1
第一步，准備文件並拷貝文件
ll percona-xtrabackup-2.0.2-461.rhel6.x86_64.rpm
scp percona-xtrabackup-2.0.2-461.rhel6.x86_64.rpm 192.168.1.11:/opt
第二步，該軟件需要依賴MySQL客戶端，所以使用yum安裝。注意，此處安裝的只是MySQL的客戶端，和本身使用源碼安裝的MySQL不沖突。
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，初始化備份。
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，這樣的備份文件無法使用，我們需要做統一檢查。
ls
2013-09-10_21-49-44
# 做統一檢查
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，模擬數據丟失。
rm -rf /usr/local/mysql/data/*
ll /usr/local/mysql/data/
第六步，恢復數據。
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，重啟mysql服務，發現報錯，pkill掉，然後啟動一切正常。
/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).
查看恢復的數據目錄，擁有者和所屬組不是mysql用戶，我們更改擁有者和所屬組。
ll /usr/local/mysql/data/
chown mysql.mysql /usr/local/mysql/data/ -R
再次啟動，仍然失敗，我們殺掉進程，再次啟動mysql，正常。
/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).
ps -ef | grep mysql
pkill -9 mysql
/etc/init.d/mysqld start
Starting MySQL.. SUCCESS!
登錄到MySQL。
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)
