Xtrabackup中主要包含兩個工具：

xtrabackup：是用於熱備份innodb, xtradb表中數據的工具，不能備份其他類型的表(Myisam表)，也不能備份數據表結構。

innobackupex：是將xtrabackup進行封裝的perl腳本，可以備份和恢復MyISAM表以及數據表結構。

但是針對myisam的備份是需要加讀鎖的，多少會對線上業務影響。但是當前絕大部分Mysql用戶，都是用innodb，所以，myisam只是系統表使用，鎖的影響，也就可以忽略了。

一段官方文檔的說明：

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

It is possible to use the xtrabackup binary alone, however, the recommend way is using it through the innobackupex wrapper script and let it execute xtrabackup for you. It might be helpful to first learn how to use innobackupex, and then learn how to use xtrabackup for having a better low-level understanding or control of the tool if needed.

這裏，我們就用Percona Xtrabackup來備份Mysql。

1. 下載軟件,進入下載鏈接

https://www.percona.com/downloads/

2. 選擇xtrabackup

3. 選擇OS版本，下載

wget https://www.percona.com/downloads/XtraBackup/Percona-XtraBackup-2.4.11/binary/redhat/6/x86_64/percona-xtrabackup-test-24-2.4.11-1.el6.x86_64.rpm

4. 安裝中可能會遇到缺少下面包的問題：

--> Processing Dependency: libev.so.4()(64bit) for package: percona-xtrabackup-24-2.4.10-1.el6.x86_64
--> Finished Dependency Resolution
Error: Package: percona-xtrabackup-24-2.4.10-1.el6.x86_64 (percona-release-x86_64)
Requires: libev.so.4()(64bit)

到下面網址，下載對應系統的rpm包，並安裝

http://rpm.pbone.net/index.php3/stat/3/srodzaj/1/search/libev.so.4

下載

wget 
ftp://ftp.pbone.net/mirror/ftp5.gwdg.de/pub/opensuse/repositories/home:/rudi_m:/devel-snap/CentOS_CentOS-6/x86_64/libev4-4.15-7.1.x86_64.rpm

安裝

rpm -ivh 
libev4-4.15-7.1.x86_64.rpm

5. 下載rpm包到本地，然後安裝，發現和現有的mysql沖突conflicts with file from package mysql-community-server

# yum localinstall percona-xtrabackup-24-2.4.10-1.el6.x86_64.rpm
......
Transaction Check Error:
file /etc/my.cnf from install of Percona-Server-shared-51-5.1.73-rel14.12.625.rhel6.x86_64 conflicts with file from package mysql-community-server-5.6.39-2.el6.x86_64

6. 先安裝一個

# yum install MySQL-shared-compat*

7. 然後再次安裝，就解決沖突問題了

# yum localinstall percona-xtrabackup-24-2.4.10-1.el6.x86_64.rpm
......
Installed:
percona-xtrabackup-24.x86_64 0:2.4.10-1.el6
Dependency Installed:
perl-DBD-MySQL.x86_64 0:4.013-3.el6                            rsync.x86_64 0:3.0.6-12.el6
Complete!

8. 備份與恢復測試

innobackupex --defaults-file=/etc/my.cnf --user=root --password='password' /backup/20180423/

手動刪除文件

/mysql/help_topic.frm
rm: remove regular file `events_stages_current.frm'? y
rm: remove regular file `events_stages_history.frm'? y
rm: remove regular file `events_stages_history_long.frm'? y
rm: remove regular file `events_stages_summary_by_account_by_event_name.frm'?

9. 整合備份文件

innobackupex --defaults-file=/etc/my.cnf  --apply-log /backup/20180423/2018-04-18_00-58-36/

10. 備份還原

innobackupex --defaults-file=/etc/my.cnf  --copy-back /backup/20180423/2018-04-18_00-58-36/

可以看到，xtrabackup已經正常工作了。

mysql備份恢復測試，請參考：

http://blog.51cto.com/hsbxxl/2107383

Percona xtrabackup 安裝與使用