Mysql 官方在线备份和数据恢复

我们从关键点开始进行；

话外：这里我们选择ext4文件格式，xfs文件系统lv、快照不可以同时挂载；

 　　快照备份的优缺点：

　　　　　　　　　　优点：可以进行在线备份，备份速度快；

　　　　　　　　　　缺点：锁表时间不可控，快照空间一定要大于需备份数据大小；

1.锁定Mysql数据库

mysql> flush tables with read lock;
Query OK, 0 rows affected (0.01 sec)

2.创建lv快照

[root@logan ~]# lvcreate -L 500M -s -n /dev/vg0/lv_sql /dev/vg0/lv0
  Logical volume "lv_sql" created.

3.挂载lv快照

[root@logan ~]# mount /dev/vg0/lv_sql /opt/

4.到这里我们就可以解锁数据库了

mysql> unlock tables;
Query OK, 0 rows affected (0.37 sec)

5.打包压缩备份好的数据

[root@logan ~]# tar -cjvf /backup/mysql.tar.bz2 /opt/*
[root@logan backup]# ls
all.sql  master.000001  master.index  mysql.tar.bz2

6.备份好数据后，我们就可以把快照删除了

[root@logan backup]# lvremove /dev/vg0/lv_sql 
Do you really want to remove active logical volume vg0/lv_sql? [y/n]: y
  Logical volume "lv_sql" successfully removed

到此为止我们的lv快照备份数据就完成了

============================================================================================================================================================

现在我们开始模拟数据丢失

[root@logan mysql]# cd data/
[root@logan data]# ls
auto.cnf        ibdata1      ibtmp1               mysql               upup
file            ib_logfile0  logan.liunx.com.err  performance_schema
ib_buffer_pool  ib_logfile1  logan.liunx.com.pid  sys
[root@logan data]# rm -rf ./*

1.进行恢复

停掉Mysql服务

[root@logan data]# killall mysqld

我们需要对压缩包进行解包

[root@logan backup]# tar -xvf mysql.tar.bz2 -C /tmp/
[root@logan opt]# cp -r ./* /usr/local/mysql/data/

2.我们cp过来的文件需要更改属主、属组

[root@logan mysql]# chown -R mysql.mysql data/
[root@logan mysql]# ll data/
总用量 110640
-rw-r----- 1 mysql mysql       56 7月   4 22:49 auto.cnf
drwxr-x--- 2 mysql mysql     4096 7月   4 22:49 file
-rw-r----- 1 mysql mysql      433 7月   4 22:51 ib_buffer_pool
-rw-r----- 1 mysql mysql 12582912 7月   4 22:49 ibdata1
-rw-r----- 1 mysql mysql 50331648 7月   4 22:49 ib_logfile0
-rw-r----- 1 mysql mysql 50331648 7月   4 22:49 ib_logfile1
-rw-r----- 1 mysql mysql    11042 7月   4 22:49 logan.liunx.com.err
drwxr-x--- 2 mysql mysql     4096 7月   4 22:49 mysql
drwxr-x--- 2 mysql mysql     4096 7月   4 22:49 performance_schema
drwxr-x--- 2 mysql mysql    12288 7月   4 22:49 sys
drwxr-x--- 2 mysql mysql     4096 7月   4 22:49 upup

3.重启Mysql服务

[root@logan mysql]# systemctl restart mysqldd

4.登录数据库查看数据

[root@logan mysql]# systemctl restart mysqldd
[root@logan mysql]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.  Commands end with ; or g.
Your MySQL connection id is 2
Server version: 5.7.25-log Source distribution

Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.

Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.

mysql> 

mysql> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| file               |
| mysql              |
| performance_schema |
| sys                |
| upup               |
+--------------------+
6 rows in set (0.00 sec)

mysql> 

mysql> use upup;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;
+----------------+
| Tables_in_upup |
+----------------+
| home           |
| t1             |
+----------------+
2 rows in set (0.00 sec)

mysql> select * from t1;
+------+-------+------+
| id   | name  | home |
+------+-------+------+
|    1 | robin |  100 |
|    2 | sdaa  |  200 |
|    3 | dfdaa |  100 |
+------+-------+------+
3 rows in set (0.00 sec)

mysql> 

数据恢复完成