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Linux九阴真经之九阴白骨爪残卷13()

时间:2018-06-17 22:18:10      阅读:282      评论:0      收藏:0      [点我收藏+]

备份还原案例

 前提:log_bin=ON

一、早上上班后误删数据库,如何恢复数据库

 

1、假设早上已经完成备份 (开启二进制),然后在students表里新增了一条数据

[root@centos7 ~]#mysqldump -A -F --single-transaction --master-data=2 > /backup/full.sql
MariaDB [hellodb]> insert students values (26,laobai,30,M,7,2);

 

2、然后在10点时,误删数据库 ;用户在访问 students表 的时候 提示错误,表找不到,然后其他用户又新增一个表

MariaDB [hellodb]> drop table students;

 MariaDB [hellodb]> insert teachers values(5,‘mht‘,‘46‘,‘M‘);

MariaDB [hellodb]> select * from students;
ERROR 1146 (42S02): Table hellodb.students doesnt exist

 

3、为了防止问题继续扩大,我们先上个只读锁,禁止用户修改。

MariaDB [(none)]> flush table with read lock;

 

4、我们先查看此时的日志文件

MariaDB [(none)]> show master logs;

+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 30343 |
| mysql-bin.000002 | 1038814 |
| mysql-bin.000003 | 7698 |
| mysql-bin.000004 | 773 |
+------------------+-----------+

 

5、为了区分新旧日志,我们刷新一下日志 

MariaDB [(none)]> flush logs;

Query OK, 0 rows affected (0.00 sec)

MariaDB [(none)]> show master logs;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 30343 |
| mysql-bin.000002 | 1038814 |
| mysql-bin.000003 | 7698 |
| mysql-bin.000004 | 816 |

 

6、我们查看一下二进制文件,确认是第四个文件且编号为245的文件 ,然后将文件导入至backup目录下

[root@centos7 ~]#less /backup/full.sql 

-- CHANGE MASTER TO MASTER_LOG_FILE=mysql-bin.000004, MASTER_LOG_POS=245;

[root@centos7 ~]#mysqlbinlog --start-position=245 /date/binlog/mysql-bin.000004 > /backup/bin.sql

 

7、上部操作是将全部备份 加上 出故障之间的备份文件导了出来,我们还需要找到删除表的记录并删除,然后利用二进制文件进行恢复 ,发现表已经全部恢复。

 

[root@centos7 backup]#vim /backup/bin.sql         #将删除表的指令删除
[root@centos7 backup]#rm -rf /date/mysql/*        #删库(删之前一定要确认有备份)
[root@centos7 backup]#systemctl restart mariadb   
[root@centos7 backup]#mysql < /backup/full.sql    #将全备份还原
[root@centos7 backup]#mysql < /backup/bin.sql     #将修改过的文件还原
[root@centos7 backup]#mysql

Database changed
MariaDB [hellodb]> select * from teachers
    -> ;
+-----+---------------+-----+--------+
| TID | Name          | Age | Gender |
+-----+---------------+-----+--------+
|   1 | Song Jiang    |  45 | M      |
|   2 | Zhang Sanfeng |  94 | M      |
|   3 | Miejue Shitai |  77 | F      |
|   4 | Lin Chaoying  |  93 | F      |
|   5 | mht           |  46 | M      |
+-----+---------------+-----+--------+

MariaDB [hellodb]> select * from students;
+-------+---------------+-----+--------+---------+-----------+
| StuID | Name          | Age | Gender | ClassID | TeacherID |
+-------+---------------+-----+--------+---------+-----------+
|     1 | Shi Zhongyu   |  22 | M      |       2 |         3 |
|     2 | Shi Potian    |  22 | M      |       1 |         7 |
|     3 | Xie Yanke     |  53 | M      |       2 |        16 |
|     4 | Ding Dian     |  32 | M      |       4 |         4 |
|     5 | Yu Yutong     |  26 | M      |       3 |         1 |
|     6 | Shi Qing      |  46 | M      |       5 |      NULL |
|     7 | Xi Ren        |  19 | F      |       3 |      NULL |
|     8 | Lin Daiyu     |  17 | F      |       7 |      NULL |
|     9 | Ren Yingying  |  20 | F      |       6 |      NULL |
|    10 | Yue Lingshan  |  19 | F      |       3 |      NULL |
|    11 | Yuan Chengzhi |  23 | M      |       6 |      NULL |
|    12 | Wen Qingqing  |  19 | F      |       1 |      NULL |
|    13 | Tian Boguang  |  33 | M      |       2 |      NULL |
|    14 | Lu Wushuang   |  17 | F      |       3 |      NULL |
|    15 | Duan Yu       |  19 | M      |       4 |      NULL |
|    16 | Xu Zhu        |  21 | M      |       1 |      NULL |
|    17 | Lin Chong     |  25 | M      |       4 |      NULL |
|    18 | Hua Rong      |  23 | M      |       7 |      NULL |
|    19 | Xue Baochai   |  18 | F      |       6 |      NULL |
|    20 | Diao Chan     |  19 | F      |       7 |      NULL |
|    21 | Huang Yueying |  22 | F      |       6 |      NULL |
|    22 | Xiao Qiao     |  20 | F      |       1 |      NULL |
|    23 | Ma Chao       |  23 | M      |       4 |      NULL |
|    24 | Xu Xian       |  27 | M      |    NULL |      NULL |
|    25 | Sun Dasheng   | 100 | M      |    NULL |      NULL |
|    26 | laobai        |  30 | M      |       7 |         2 |
+-------+---------------+-----+--------+---------+-----------+

 

Linux九阴真经之九阴白骨爪残卷13()

原文:https://www.cnblogs.com/huxiaojun/p/9193806.html

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