mysql备份和恢复

一、备份准备工作

1.查看服务器状态

mysql> \s
--------------
mysql  Ver 14.14 Distrib 5.5.37, for Linux (x86_64) using  EditLine wrapper

Connection id:		5
Current database:
Current user:		root@localhost
SSL:			Not in use
Current pager:		stdout
Using outfile:		''
Using delimiter:	;
Server version:		5.5.37 Source distribution
Protocol version:	10
Connection:		127.0.0.1 via TCP/IP
Server characterset:	utf8
Db     characterset:	utf8
Client characterset:	utf8
Conn.  characterset:	utf8
TCP port:		3306
Uptime:			45 min 22 sec

Threads: 1  Questions: 17  Slow queries: 0  Opens: 41  Flush tables: 1  Open tables: 4  Queries per second avg: 0.006
--------------

2.查看数据目录存放位置

mysql> show variables like '%datadir%';
+---------------+-------------------+
| Variable_name | Value             |
+---------------+-------------------+
| datadir       | /data/mysql/data/ |
+---------------+-------------------+
1 row in set (0.02 sec)

3.修改my.cnf

[root@nagios-client ~]# vim /etc/my.cnf
log-bin=mysql-bin
innodb_file_per_table = 1

重启mysqld服务

[root@nagios-client ~]# service mysqld restart
Shutting down MySQL. SUCCESS!
Starting MySQL.. SUCCESS!

4.查看新生成的binlog日志

[root@nagios-client ~]# ll /data/mysql/data/
total 28700
-rw-rw---- 1 mysql mysql 18874368 Jun  2 16:30 ibdata1
-rw-rw---- 1 mysql mysql  5242880 Jun  2 16:30 ib_logfile0
-rw-rw---- 1 mysql mysql  5242880 Jun  2 15:37 ib_logfile1
drwx------ 2 mysql root      4096 Jun  2 15:37 mysql
-rw-rw---- 1 mysql mysql      107 Jun  2 16:30 mysql-bin.000001
-rw-rw---- 1 mysql mysql       19 Jun  2 16:30 mysql-bin.index
srwxrwxrwx 1 mysql mysql        0 Jun  2 16:30 mysql.sock
-rw-r----- 1 mysql root      3375 Jun  2 16:30 nagios-client.err
-rw-rw---- 1 mysql mysql        6 Jun  2 16:30 nagios-client.pid
drwx------ 2 mysql mysql     4096 Jun  2 15:37 performance_schema
drwx------ 2 mysql root      4096 Jun  2 15:37 test

5.准备一个test库，里面有两张表，t1表和t2表！
第一张t1表，使用的是MyISAM引擎，其中有1亿多行数据，第二张t2表,使用的是INNODB引擎，其中有2千多万行数据！

mysql> create table t1 (id int(10) default null)engine=myisam default charset=utf8;
Query OK, 0 rows affected (0.01 sec)    #创建一个简单的t1表，里面只有一个字段 id

mysql> show create table t1;
+-------+--------------------------------------------------------------------------------------+
| Table | Create Table                                                                         |
+-------+--------------------------------------------------------------------------------------+
| t1    | CREATE TABLE `t1` (
`id` int(10) DEFAULT NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8 |
+-------+--------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

mysql>insert into t1 values(1),(2),(3),(4),(5),(6),(7),(8),(9),(10); #先插入十个数据

mysql> insert into t1 select * from t1;

mysql> select count(*) from t1;
+-----------+
| count(*)  |
+-----------+
| 335544320 |
+-----------+
1 row in set (0.04 sec)

t2表

mysql> create table t2 (id int(10) default null)engine=innodb default charset=utf8;
Query OK, 0 rows affected (0.14 sec)

mysql> show create table t2;
+-------+--------------------------------------------------------------------------------------+
| Table | Create Table                                                                         |
+-------+--------------------------------------------------------------------------------------+
| t2    | CREATE TABLE `t2` (
`id` int(10) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 |
+-------+--------------------------------------------------------------------------------------+
1 row in set (0.02 sec)

mysql> insert into t2 values(1),(2),(3),(4),(5),(6),(7),(8),(9),(10);

二、备份策略具体演示
1.策略一：直接拷贝数据库文件（文件系统备份工具 cp）（适合小型数据库）
(1).标准流程：锁表->刷新表到磁盘->拷贝文件->解锁（注,若有有可能的话，可以先停止数据库，再用cp命令准备，这样备份的数据最可靠）
(2).具体步骤：
a.打开第一个终端，

mysql> flush tables with read lock;
Query OK, 0 rows affected (0.06 sec)

b.打开第二个终端

[root@nagios-client ~]# mkdir /root/alldb.`date +%F-%H-%M-%S`/  #创建备份目录
[root@nagios-client ~]# cp -rp /data/mysql/data/* /root/alldb.2015-06-02-16-56-27/ #复制所以的数据库文件

c.在第一个终端解锁

mysql> unlock tables;
Query OK, 0 rows affected (0.08 sec)

[root@nagios-client ~]# ll /root/alldb.2015-06-02-16-56-27/    #查看备份好的数据库
total 372772
-rw-rw---- 1 mysql mysql 371195904 Jun  2 16:52 ibdata1
-rw-rw---- 1 mysql mysql   5242880 Jun  2 16:52 ib_logfile0
-rw-rw---- 1 mysql mysql   5242880 Jun  2 16:52 ib_logfile1
drwx------ 2 mysql root       4096 Jun  2 15:37 mysql
-rw-rw---- 1 mysql mysql     11027 Jun  2 16:52 mysql-bin.000001
-rw-rw---- 1 mysql mysql        19 Jun  2 16:30 mysql-bin.index
srwxrwxrwx 1 mysql mysql         0 Jun  2 16:30 mysql.sock
-rw-r----- 1 mysql root       3375 Jun  2 16:30 nagios-client.err
-rw-rw---- 1 mysql mysql         6 Jun  2 16:30 nagios-client.pid
drwx------ 2 mysql mysql      4096 Jun  2 15:37 performance_schema
drwx------ 2 mysql root       4096 Jun  2 16:45 test

(3).模拟数据库损坏
直接删除数据目录中的所有文件

[root@nagios-client ~]# cd /data/mysql/data/
[root@nagios-client data]# ll
total 372776
-rw-rw---- 1 mysql mysql 371195904 Jun  2 16:52 ibdata1
-rw-rw---- 1 mysql mysql   5242880 Jun  2 16:52 ib_logfile0
-rw-rw---- 1 mysql mysql   5242880 Jun  2 16:52 ib_logfile1
drwx------ 2 mysql root       4096 Jun  2 15:37 mysql
-rw-rw---- 1 mysql mysql     11027 Jun  2 16:52 mysql-bin.000001
-rw-rw---- 1 mysql mysql        19 Jun  2 16:30 mysql-bin.index
srwxrwxrwx 1 mysql mysql         0 Jun  2 16:30 mysql.sock
-rw-r----- 1 mysql root       3375 Jun  2 16:30 nagios-client.err
-rw-rw---- 1 mysql mysql         6 Jun  2 16:30 nagios-client.pid
drwx------ 2 mysql mysql      4096 Jun  2 15:37 performance_schema
drwx------ 2 mysql root       4096 Jun  2 16:45 test
[root@nagios-client data]# rm -rf *

(4).具体还原步骤
a.mysql这时是无法停止的

[root@nagios-client data]# service mysqld stop
ERROR! MySQL server PID file could not be found!

b.查找mysql所有进程

[root@nagios-client data]# killall mysqld

c.初始化mysql

[root@nagios-client data]# /usr/local/mysql/scripts/mysql_install_db --basedir=/usr/local/mysql/ --datadir=/data/mysql/data/ --user=mysql

d.复制完全备份的数据文件到数据目录中

[root@nagios-client data]# cp -r /root/alldb.2015-06-02-16-56-27/ /data/mysql/data/

e.启动mysql数据库

[root@nagios-client data]# service mysqld start
Starting MySQL.. SUCCESS!

f.测试并查看数据

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
4 rows in set (0.09 sec)

mysql> use test;
Database changed
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| t1             |
| t2             |
+----------------+
2 rows in set (0.00 sec)

mysql> select count(*) from t1;
+-----------+
| count(*)  |
+-----------+
| 335544320 |
+-----------+
1 row in set (0.06 sec)

mysql> select count(*) from t2;
+----------+
| count(*) |
+----------+
| 41943040 |
+----------+
1 row in set (15.37 sec)

(5).总结cp命令，对其进行的备份，速度快，还原速度几乎最快，但是灵活度很低，可以跨系统，但是跨平台能力很差，适合小型数据库备份！2.策略二：mysqldump备份数据库（完全备份+增加备份，速度相对较慢，适合中小型数据库）（MyISAM是温备份，InnoDB是热备份）
(1).mysqldump命令详解

mysqldump --all-databases --lock-all-tables --routines --triggers --events --master-data=2 --flush-logs > /root/2013-07-22-16-20.full.sql
--all-tables #备份所有库
--lock-all-tables #为所有表加读锁
--routinge #存储过程与函数
--triggers #触发器
--events #记录事件
--master-data=2 #在备份文件中记录当前二进制日志的位置，并且为注释的，1是不注释掉在主从复制中才有意义
--flush-logs #日志滚动一次

(2).具体备份过程如下
a.查看备份前的binlog日志

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000005 |      107 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

b.备份所有库（完全备份）

mysqldump -u root -p -h 127.0.0.1 --all-databases --lock-all-tables --master-data=2 --flush-logs >/root/full.sql

c.查看备份是否成功

[root@nagios-client ~]# ll -h /root/ |grep full
-rw-r--r--   1 root root  1.5G Jun  3 09:35 full.sql

d.查看新生成的binlog日志

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000006 |      107 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

e.插入几条新的数据

mysql> use test;
Database changed
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| t1             |
| t2             |
+----------------+
2 rows in set (0.00 sec)

mysql> insert into t1 values(335544321),(335544322),(335544323);
Query OK, 3 rows affected (0.03 sec)
Records: 3  Duplicates: 0  Warnings: 0

f.再次查看binlog日志

mysql> show master status;
+------------------+----------+--------------+------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000006 |      363 |              |                  |
+------------------+----------+--------------+------------------+
1 row in set (0.00 sec)

g.备份二进制日志（增量备份）

[root@nagios-client ~]# cp /data/mysql/data/mysql-bin.000006 /root

i.模拟数据库损坏

mysql> drop database test;        #这里我们删掉test库
Query OK, 2 rows affected (0.38 sec)

(3).具体还原过程如下

#首先通过全备还原test库
mysql> system ls -l /root |grep full
-rw-r--r--   1 root root  1548283305 Jun  3 09:35 full.sql
mysql> system pwd
/root
mysql> source full.sql

a.查看还原结果

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test               |
+--------------------+
4 rows in set (0.08 sec)

mysql> use test;
Database changed
mysql> show tables;
+----------------+
| Tables_in_test |
+----------------+
| t1             |
| t2             |
+----------------+
2 rows in set (0.00 sec)

b.查看t1表最后10条数据

mysql> select * from t1 order by id desc limit 10;
+------+
| id   |
+------+
|   10 |
|   10 |
|   10 |
|   10 |
|   10 |
|   10 |
|   10 |
|   10 |
|   10 |
|   10 |
+------+
10 rows in set (32.60 sec)

#从结果能看出，我们后来插入的数据没有了

c.下面恢复后来插入的数据

#通过之前备份的二进制日志文件还原
[root@nagios-client ~]# mysqlbinlog /root/mysql-bin.000006 |mysql -u root -p -h 127.0.0.1 test
mysql> select * from t1 order by id desc limit 10;
+-----------+
| id        |
+-----------+
| 335544323 |
| 335544322 |
| 335544321 |
|        10 |
|        10 |
|        10 |
|        10 |
|        10 |
|        10 |
|        10 |
+-----------+
10 rows in set (30.39 sec)
#从这里能看到数据已恢复

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