MySQL什么是物理备份（lvm-snapshot）

1、flush table with read locak; 
2、create snapshot 
3、show master status;　show slave status; [可选]
4、unlock tables;
5、Copy files from the snapshot
6、Unmount the snapshot. 
7、Remove snapshot

快照备份：
1.迁移数据到逻辑卷（不是必须，视情况而定）
2.锁表（时间）
3.给数据库所在的逻辑卷拍快照
4.解锁
5.将快照挂载到临时挂载点上
6.将快照上的所有数据拷贝到相应的备份目录里（不同主机）
7.卸载快照并删除

[root@Admin ~]# pvcreate /dev/sdb
[root@Admin ~]# vgcreate vg01 /dev/sdb
[root@Admin ~]# lvcreate -n lv_mysql -L 4G vg01
[root@Admin ~]# mkfs.ext4 /dev/mapper/vg01-lv_mysql

1>先停止应用
2>停止mysql服务
[root@Admin ~]# service mysqld stop
3>备份所有的数据文件到指定的地方
[root@Admin ~]# tar -czvf /tmp/backmysql/mysql.tar.gz /data/DB/*
4>挂载逻辑卷到当前mysql的数据目录里
[root@Admin ~]# mount /dev/mapper/vg01-lv_mysql /data/DB/
5>将刚刚备份的数据解压到数据目录里
[root@Admin ~]# tar xf /tmp/backmysql/mysql.tar.gz -C /data/DB/
[root@Admin ~]# mv /data/DB/data/DB/* /data/DB/ && rm -rf /data/DB/data/
6>启动数据库
[root@Admin ~]# service mysqld start
此处启动失败原因/data/DB/数据目录的权限变成了root，
更改权限重新启动
[root@Admin ~]# chown mysql. -R /data/DB/ && service mysqld start

mysql> flush table with read lock;

[root@Admin ~]# lvcreate -n lv_mysql_s -L 50M -s /dev/vg01/lv_mysql
[root@Admin ~]# dmsetup --tree ls
vg01-lv_mysql (253:0)
 └─vg01-lv_mysql-real (253:1)
 └─ (8:16)
vg01-lv_mysql_s (253:3)
 ├─vg01-lv_mysql_s-cow (253:2)
 │ └─ (8:16)
 └─vg01-lv_mysql-real (253:1)
 └─ (8:16)

[root@Admin ~]# unlock tables

[root@Admin ~]# echo "flush tables with read lock; system lvcreate -n lv_mysql_s -L 50M -s /dev/vg01/lv_mysql;unlock tables;" |mysql -p123

[root@Admin ~]# mkdir /mnt/mysql && mount /dev/vg01/lv_mysql_s /mnt/mysql/

[root@Admin ~]# ls /mnt/mysql/ # 可以看到新的挂载目录里面的数据
Admin.pid db01 ib_logfile0 mysql mysql-bin.000003 mysql-bin.000006 mysql-bin.000009 performance_schema
auto.cnf db02 ib_logfile1 mysql-bin.000001 mysql-bin.000004 mysql-bin.000007 mysql-bin.000010 test
binlog ibdata1 login mysql-bin.000002 mysql-bin.000005 mysql-bin.000008 mysql-bin.index
[root@Admin ~]# mkdir /backup && rsync -av /mnt/mysql /backup

[root@Admin ~]# umount /mnt/mysql/ && lvremove /dev/vg01/lv_mysql_s

 1>我们来点狠的，直接把mysql的数据目录/data/DB/删除。
 [root@Admin ~]# rm -rf /data/DB/* && ls /data/DB/
 2>删除后可以看到重启mysql直接报错了
 [root@Admin ~]# service mysqld restart 
 MySQL server PID file could not be found! [失败]
 Starting MySQL...The server quit without updating PID file [失败]/DB/Admin.pid).
 3>根据上面的/backup里面备份的数据进行恢复
 [root@Admin ~]# mv /backup/mysql/* /data/DB/
 [root@Admin ~]# ls /data/DB/
 auto.cnf db02 ib_logfile1 mysql-bin.000001 mysql-bin.000004 mysql-bin.000007 mysql-bin.000010 test
 binlog ibdata1 login mysql-bin.000002 mysql-bin.000005 mysql-bin.000008 mysql-bin.index
 db01 ib_logfile0 mysql mysql-bin.000003 mysql-bin.000006 mysql-bin.000009 performance_schema
 4>重新启动
 [root@Admin ~]# chown mysql. /data/DB/ -R 
 [root@Admin ~]# service mysqld restart
 这里权限更改了如果启动还是报错的话，查看下是否mysql进程还存在，如果存在，将其kill掉再重启就OK
 [root@Admin ~]# mysql -p123
 mysql> show databases;
 +--------------------+
 | Database |
 +--------------------+
 | information_schema |
 | binlog |
 | db01 |
 | db02 |
 | login |
 | mysql |
 | performance_schema |
 | test |
 +--------------------+
rows in set (0.00 sec)

#!/bin/bash
#LVM BackMysql
back_dir=/backup/`date +%F`
[ -d $back_dir ] mkdir -p $back_dir
echo "flush tables with read lock; system lvcreate -n lv_mysql_s -L 50M -s /dev/vg01/lv_mysql;unlock tables;" |mysql -p123
mount /dev/vg01/lv_mysql_s /mnt/mysql/
rsync -a /mnt/mysql/ $back_dir
if [ $? -eq 0 ];then
 umount /mnt/mysql/ && lvremove -f /dev/vg01/lv_mysql_s
fi

正常安装MySQL：
1. 安装系统
2. 准备LVM，例如 /dev/vg_back/lv-mysql，mount /usr/local/mysql
3. 源码安装MySQL到 /usr/local/mysql

可选操作：　将现在的数据迁移到LVM
1. 准备lvm及文件系统
# lvcreate -L 2G -n lv-mysql vg_back
# mkfs.ext4 /dev/vg_back/lv-mysql
 
2. 将数据迁移到LVM
# service mysqld stop
# mount /dev/vg_back/lv-mysql /u01/ //临时挂载点
# rsync -va /usr/local/mysql/ /u01/ //将MySQL原数据镜像到临时挂载点

# umount /u01/
# mount /dev/vg_back/lv-mysql /usr/local/mysql //加入fstab开机挂载
# df -Th
/dev/mapper/vg_back-lv-mysql ext4 2.0G 274M 1.7G 15% /usr/local/mysql
# service mysqld start

手动基于LVM快照实现备份：
1. 加锁
mysql> flush table with read lock;

2.创建快照
# lvcreate -L 500M -s -n lv-mysql-snap /dev/vg_back/lv-mysql
# mysql -uroot -p123 -e 'show master status' > /backup/`date +%F`_position.txt
或者
mysql> show master status;
+-------------------+----------+--------------+------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-------------------+----------+--------------+------------------+-------------------+
| mysqld-bin.00003 | 135 | | | |
+-------------------+----------+--------------+------------------+-------------------+

3. 释放锁
mysql> unlock tables;

4. 从快照中备份
# mount -o ro /dev/vg_back/lv-mysql-snap /u01/
# mkdir /backup/`date +%F`
# rsync -a /u01/ /backup/2015-07-02/

5. 移除快照
# umount /u01/
# lvremove -f /dev/vg_back/lv-mysql-snap

脚本 + Cron完成：
#!/bin/bash
#LVM backmysql...
back_dir=/backup/`date +%F`

[ -d $back_dir ] || mkdir -p $back_dir

mysql -uroot -p123 -e 'flush table with read lock'
lvcreate -L 500M -s -n lv-mysql-snap /dev/vg_back/lv-mysql
mysql -uroot -p123 -e 'show master status' |grep mysql > $back_dir/position.txt
mysql -uroot -p123 -e 'flush logs'
mysql -uroot -p123 -e 'unlock tables'

mount -o ro /dev/vg_back/lv-mysql-snap /u01

rsync -a /u01/ $back_dir

if [ $? -eq 0 ];then
umount /u01/
lvremove -f /dev/vg_back/lv-mysql-snap
fi
===============================================================
mylvmbackup

功能：利用LVM快照实现物理备份，即LVM快照备份的自动版

安装perl模块
1. 在线安装
http://www.lenzg.net/mylvmbackup
它依赖于perl 模块，可用以下命令安装
perl -MCPAN -e 'install Config::IniFiles'

2. 离线安装
# rpm -ivh mylvmbackup-0.16-0.noarch.rpm
warning: mylvmbackup-0.16-0.noarch.rpm: Header V4 DSA/SHA1 Signature, key ID b27291f2: NOKEY
error: Failed dependencies:
perl(Config::IniFiles) is needed by mylvmbackup-0.16-0.noarch
perl(Date::Format) is needed by mylvmbackup-0.16-0.noarch
perl(File::Copy::Recursive) is needed by mylvmbackup-0.16-0.noarch

解决：
# yum -y localinstall atrpms-77-1.noarch.rpm perl-File-Copy-Recursive-0.38-1.el6.rfx.noarch.rpm perl-IO-stringy-2.110-1.2.el6.rfx.noarch.rpm perl-Config-IniFiles-2.56-1.el6.rf.noarch.rpm

安装mylvmbackup软件包
# yum -y install mylvmbackup-0.15-0.noarch.rpm 解决依赖关系perl-TimeDate

备份方法一：
# mylvmbackup --user=root --password=123 --host=localhost --mycnf=/etc/my.cnf --vgname=vg_back --lvname=lv-mysql --backuptype=tar --lvsize=100M --backupdir=/backup

# tar xf backup-20140903_000236_mysql.tar.gz
# ls
backup backup-cnf-20150702_000236_mysql
backup-20150702_000236_mysql.tar.gz backup-pos

备份方法二：
# vim /etc/mylvmbackup.conf
[mysql] #连接数据库配置
user=root
password=123456
host=localhost
port=3306
socket=/tmp/mysql.sock
mycnf=/etc/my.cnf
[lvm] #LVM逻辑卷的配置
vgname=vg_server #卷组名称
lvname=lv_mysql #逻辑卷名称
backuplv=mysql_snap #快照卷名称
lvsize=500M
[fs] #文件系统配置
xfs=0
mountdir=/var/tmp/mylvmbackup/mnt/ #挂载目录
backupdir=/backup #备份目录，也可以备份到行程主机
[misc] #定义备份选项
backuptype=tar #定义备份的类型
backupretention=0
prefix=backup #定义备份文件名前缀
suffix=_mysql #定义备份文件名后缀
tararg=cvf #定义tar参数，默认为cvf
tarfilesuffix=.tar.gz #定义备份文件后缀名格式
datefmt=%Y%m%d_%H%M%S #定义备份文件名时间戳格式
keep_snapshot=0 #是否保留snaphot
keep_mount=0 #是否卸载snaphot
quiet=0 #定义记录日志类型
注释：其他配置保持输入即可

然后直接执行mylvmbackup即可

mylvmbackup 参考示例