使用Amanda ZRM备份远程MySQL数据库

本文写道最后的时候，我才发现ZRM for MySQL的一个致命问题，就我目前的理解和测试来看，它恢复数据的时候是采取覆盖的方式，举个例子，假定某台数据库服务器上有两个数据库test1,test2，你备份了这两个数据库，某一天，test2数据库里的某一个表坏了，那么它无法做到仅仅只是恢复损坏的表，甚至无法做到仅仅恢复test2，而是直接把test1,test2都恢复。那这绝对是一个噩梦。
但愿我目前的理解是错误的，只是我实在找不到控制恢复粒度的地方。下面的文字就当闲着无聊看看吧。

Zmanda Recovery Manager(ZRM)提供了备份MySQL数据库的能力，并且支持两种备份模式：逻辑备份和裸备份，有关详细的介绍，可以看官方的介绍。下面给出一个备份的实例。

先介绍备份的环境，如果大家看过之前的那篇Amanda集中备份实例，那么大概就知道是什么样的一个网络架构了，承接上文，这里备份服务器还是cp1.domain.com，MySQL数据库分别运行在cp2.domain.com和cp3.domain.com上，需要备份其所有的数据库。

一、服务端的安装和配置
首先从官方站点下载对应系统的服务端程序，然后安装。注意：服务端与perl-DBI,MySQL-client程序库有依赖关系，安装之前先安装这个两个包。

安装完后,/etc/mysql-zrm/是其配置文件的所在地。/etc/mysql-zrm/目录下有一个mysql-zrm.conf文件，这是最重要的配置文件。在/etc/mysql-zrm/目录下，你可以创建一些目录，每一个目录就是一个备份集的名称，我这里为了直观，采取了主机名的方式来创建备份集

mkdir /etc/mysql-zrm/{cp2.domain.com,cp3.domain.com}
cp  /etc/mysql-zrm/{mysql-zrm.conf,cp2.domain.com/,cp3.domain.com/}

/etc/mysql-zrm/mysql-zrm.conf可以做为全局配置文件，针对每一台需要备份的数据库的不同，可以在备份集目录里的mysql-zrm.conf再定义，这里的定义可以覆盖全局定义。

首先，我们把一些全局定义信息配置在/etc/mysql-zrm/mysql-zrm.conf文件里

#cat /etc/mysql-zrm/mysql-zrm.conf
backup-level=0
backup-mode=logical
backup-type=regular
destination=/yourpath/db
compress=1
compress-plugin=/bin/gzip
encrypt=1
encrypt-plugin="/usr/share/mysql-zrm/plugins/encrypt.pl"
decrypt-option="-d"
all-databases=1
user="backup-user"
password="securepassword"
mailto="your＠domain.com"

上面的配置信息应该比较直观。
然后配置每一台MySQL服务器的一些特有参数

#cat /etc/mysql-zrm/cp2.domain.com/mysql-zrm.conf
host="cp2.domain.com"
destination=/yourpath/db
 
#cat /etc/mysql-zrm/cp3.domain.com/mysql-zrm.conf
host="cp3.domain.com"
destination=/yourpath/db

创建加密的密码文件

[root@cp1:~# touch /etc/mysql-zrm/.passphrase
[root@cp1:~# echo encryptpass > /etc/mysql-zrm/.passphrase
[root@cp1:~# chmod 700 /etc/mysql-zrm/.passphrase

二、配置客户端
这里有两台机器，cp2和cp3，因为我们备份的类型一样，所以cp2的配置过程和cp3的配置过程一样，这里只描述cp2的配置过程
1.登录cp2服务器
2.用MySQL的管理员帐号（一般是root）登录MySQL数据库

mysql -uroot -p
Enter password:
Welcome TO the MySQL monitor.  Commands end WITH ; OR \g.
Your MySQL connection id IS 38208
Server version: 5.0.45-log Source distribution
 
Type 'help;' OR '\h' FOR help. Type '\c' TO clear the buffer.
 
mysql>

3.创建一个用户备份的帐号并授予一定的权限,帐号的定义在备份服务器的/etc/mysql-zrm/mysql-zrm.conf文件里有定义，这里帐号是backup-user，密码是securepassword

mysql> GRANT SELECT, INSERT, UPDATE, CREATE, DROP, reload, shutdown,
    -> ALTER, super, LOCK TABLES, replication client ON *.* TO
    -> 'backup-user'@'cp1.domain.com' IDENTIFIED BY 'securepassword';

提示：如果你需要备份的数据库不是全部，那么在授权的时候，最好是指定，而不是上面的*.*方式，安全为主！

三、测试备份
配置还是比较简单的，现在我们开始测试。
首先的用root帐号登录cp1机器，然后执行下面的指令：

root@cp1:/etc/mysql-zrm# mysql-zrm --action backup --backup-level 0 --backup-set cp3.domain.com
backup:INFO: ZRM for MySQL Community Edition - version 2.1
cp3.domain.com:backup:INFO: START OF BACKUP
cp3.domain.com:backup:INFO: PHASE START: Initialization
cp3.domain.com:backup:INFO: The quick backup-type is supported only for snapshot backups. Setting backup-type to 'regular'
cp3.domain.com:backup:WARNING: Binary logging is off.
cp3.domain.com:backup:INFO: backup-set=cp3.domain.com
cp3.domain.com:backup:INFO: backup-date=20090415180321
cp3.domain.com:backup:INFO: mysql-server-os=Linux/Unix
cp3.domain.com:backup:INFO: backup-type=regular
cp3.domain.com:backup:INFO: host=cp3.3yidc.cn
cp3.domain.com:backup:INFO: backup-date-epoch=1239789801
cp3.domain.com:backup:INFO: mysql-zrm-version=ZRM for MySQL Community Edition - version 2.1
cp3.domain.com:backup:INFO: mysql-version=5.0.45
cp3.domain.com:backup:INFO: backup-directory=/yourpath/db/cp3.domain.com/20090415180321
cp3.domain.com:backup:INFO: backup-level=0
cp3.domain.com:backup:INFO: backup-mode=logical
cp3.domain.com:backup:INFO: PHASE END: Initialization
cp3.domain.com:backup:INFO: PHASE START: Running pre backup plugin
cp3.domain.com:backup:INFO: PHASE END: Running pre backup plugin
cp3.domain.com:backup:INFO: PHASE START: Flushing logs
cp3.domain.com:backup:INFO: PHASE END: Flushing logs
cp3.domain.com:backup:INFO: PHASE START: Creating logical backup
cp3.domain.com:backup:INFO: logical-databases=apachelogs dtc fireyang hnnoritz mysql s567 wordpress
cp3.domain.com:backup:INFO: PHASE END: Creating logical backup
cp3.domain.com:backup:INFO: PHASE START: Calculating backup size & checksums
cp3.domain.com:backup:INFO: last-backup=/csdata/backup/db/cp3.domain.com/20090415180226
cp3.domain.com:backup:INFO: backup-size=4.04 MB
cp3.domain.com:backup:INFO: PHASE END: Calculating backup size & checksums
cp3.domain.com:backup:INFO: PHASE START: Compression/Encryption
cp3.domain.com:backup:INFO: compress=/bin/gzip
cp3.domain.com:backup:INFO: encrypt=/usr/share/mysql-zrm/plugins/encrypt.pl
cp3.domain.com:backup:INFO: decrypt-option=-d
cp3.domain.com:backup:INFO: backup-size-compressed=0.46 MB
cp3.domain.com:backup:INFO: PHASE END: Compression/Encryption
cp3.domain.com:backup:INFO: read-locks-time=00:00:02
cp3.domain.com:backup:INFO: flush-logs-time=00:00:00
cp3.domain.com:backup:INFO: compress-encrypt-time=00:00:02
cp3.domain.com:backup:INFO: backup-time=00:00:02
cp3.domain.com:backup:INFO: backup-status=Backup succeeded
cp3.domain.com:backup:INFO: Backup succeeded
cp3.domain.com:backup:INFO: PHASE START: Running post backup plugin
cp3.domain.com:backup:INFO: PHASE END: Running post backup plugin
cp3.domain.com:backup:INFO: PHASE START: Mailing backup report
cp3.domain.com:backup:INFO: PHASE END: Mailing backup report
cp3.domain.com:backup:INFO: PHASE START: Cleanup
cp3.domain.com:backup:INFO: PHASE END: Cleanup
cp3.domain.com:backup:INFO: END OF BACKUP

以上是备份cp3.domain.com的数据库，用同样的指令可以备份cp2.domain.com数据库。

4、检验
如果上述备份过程没有报错，那么接下来就要看看备份的数据是不是有效了。在cp1机器上执行下面的指令

root@cp1:~# mysql-zrm --action  verify-backup --backup-set cp3.domain.com
verify-backup:INFO: ZRM for MySQL Community Edition - version 2.1
cp3.domain.com:verify-backup:INFO: Verification successful
 
root@cp1:~# mysql-zrm --action  verify-backup --backup-set cp2.domain.com
verify-backup:INFO: ZRM for MySQL Community Edition - version 2.1
cp2.domain.com:verify-backup:INFO: Verification successful

校验都没有报错，我们还可以看看备份的性能，备份的详细信息等，更多的使用方式，可以查看mysql-zrm(1)

root@cp1:~# mysql-zrm --action report --show backup-performance-info
 
REPORT TYPE : backup-performance-info
 
backup_set  backup_date                  backup_level     backup_size  backup_size_compressed     backup_time
----------------------------------------------------------------------------------------------------------------------------------------------------------------
cp3.domain.com  Wed 15 Apr 2009 06:03:21                0         4.04 MB  0.46 MB                    00:00:02
cp3.domain.com  Wed 15 Apr 2009 06:02:26                0         4.04 MB  0.46 MB                    00:00:02
cp3.domain.com  Wed 15 Apr 2009 06:01:38                0         4.04 MB  0.46 MB                    00:00:03
cp2.domain.com  Wed 15 Apr 2009 05:19:57                0       315.05 MB  121.38 MB                  00:02:36
cp3.domain.com  Wed 15 Apr 2009 05:19:33                0         4.03 MB  0.46 MB                    00:00:02
 
root@cp1:~# mysql-zrm --action list --backup-set cp3.domain.com
list:INFO: ZRM for MySQL Community Edition - version 2.1
0 /csdata/backup/db/cp3.domain.com/20090415180321
Index File
{	decrypt-option=-d
	backup-status=Backup succeeded
	mysql-version=5.0.45
	backup-date=20090415180321
	mysql-zrm-version=ZRM for MySQL Community Edition - version 2.1
	compress-encrypt-time=00:00:02
	backup-type=regular
	logical-databases=apachelogs dtc fireyang hnnoritz mysql s567 wordpress
	mysql-server-os=Linux/Unix
	backup-level=0
	last-backup=/csdata/backup/db/cp3.domain.com/20090415180226
	backup-size-compressed=0.46 MB
	backup-size=4.04 MB
	encrypt=/usr/share/mysql-zrm/plugins/encrypt.pl
	backup-set=cp3.domain.com
	backup-time=00:00:02
	host=cp3.3yidc.cn
	backup-directory=/csdata/backup/db/cp3.domain.com/20090415180321
	flush-logs-time=00:00:00
	read-locks-time=00:00:02
	compress=/bin/gzip
	backup-date-epoch=1239789801
}
root@cp1:~#

五、恢复

假定cp2服务器上的数据库ehcpbackup20090403170240丢失了（这里是我人工删除了这个库），我们看看如何从备份里恢复。

1.登录cp1机器
2.执行下面的命令，看看cp2机器上的数据库现在备份在哪里(为了显示直观，输出结果有处理）

root@cp1:~# mysql-zrm-reporter --show restore-info --where backup-set=cp2.domain.com
 
REPORT TYPE : restore-info
 
backup_set  backup_date      backup_level  backup_directory
------------------------------------------------------------------------------
cp3.domain.com  15/4 2009    0  /yourpath/db/cp2.domain.com/20090415171957

3.然后执行真正的备份指令：

root@cp1:~#mysql-zrm --action restore --backup-set cp2.domain.com --source-directory \
> /yourpath/db/cp2.domain.com/20090415171957
INFO: ZRM for MySQL Enteprise Edition - version 1.1
WARNING: Binary logging is off. Incremental backups cannot be done.
INFO: Restore done in 169 seconds.
MySQL server has been shutdown. Please restart after verification.

4.重启cp2机器上的MySQL服务。
到此恢复完成。