场景：周日全备份，周一，周二增量备份，周三出现问题，数分钟后发现；
数据库的安装：
yum install mariadb-server -y
systemctl start mariadb
yum install percona-xtrabackup-24-2.4.9-1.el7.x86_64.rpm
在10.2的高版本上默认即时innodb_file_per_table；这里的版本是5.5，暂时没开启，需要手动写到配置文件中。
[root@mysql ~]$ vim /etc/my.cnf
[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
innodb_file_per_table
log_bin[root@mysql ~]$mysql < hellodb_InnoDB.sql
全备份：
[root@mysql ~]$mkdir -pv /backups
[root@mysql ~]$ll /backups
total 0
[root@mysql ~]$innobackupex /backups/
周一数据修改后；晚上对数据进行增量备份；
MariaDB [(none)]> use hellodb;
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
MariaDB [hellodb]> insert students(name,age,gender) values('a','28','F');
Query OK, 1 row affected (0.01 sec)
[root@mysql ~]$mkdir /backups/{inc1,inc2} -pv
mkdir: created directory ‘/backups/inc1’
mkdir: created directory ‘/backups/inc2’
[root@mysql ~]$innobackupex --incremental /backups/inc1/ --incremental-basedir=/backups/2018-02-25_15-21-53/
--incremental /backups/inc1/是指这是增量备份，以及备份的位置；
--incremental-basedir=/backups/2018-02-25_15-21-53/是指基于哪个全备份或者增量备份的增量备份；
[root@mysql ~]$ll /backups/
total 0
drwxr-x--- 6 root root 187 Feb 25 15:21 2018-02-25_15-21-53
drwxr-xr-x 3 root root 33 Feb 25 15:31 inc1
drwxr-xr-x 2 root root 6 Feb 25 15:25 inc2
[root@mysql ~]$ll /backups/inc1/
total 0
drwxr-x--- 6 root root 213 Feb 25 15:31 2018-02-25_15-31-17
周二的时候修改数据，并进行增量备份；
MariaDB [hellodb]> insert students(name,age,gender) values('b','28','F');
Query OK, 1 row affected (0.01 sec)
[root@mysql ~]$innobackupex --incremental /backups/inc2/ --incremental-basedir=/backups/inc1/2018-02-25_15-31-17/
[root@mysql ~]$du -sh /backups/
23M /backups/
[root@mysql ~]$scp -pr /backups/ 192.168.27.17:/app/
[root@mysql17 ~]$ls /app/backups/
2018-02-25_15-21-53 inc1 inc2
[root@mysql17 ~]$数据库的还原与数据整理操作：
备份还原：
还原的过程中MySQL服务是不启动的；
数据预整理：
[root@mysql17 ~]$innobackupex --apply-log --redo-only /app/backups/2018-02-25_15-21-53/
--redo-only表示有相应的增量备份；
将第一次增量备份的数据合并到完全备份中；
[root@mysql17 ~]$innobackupex --apply-log --redo-only /app/backups/2018-02-25_15-21-53/ --incremental-dir=/app/backups/inc1/2018-02-25_15-31-17/
将第二次增量备份的数据合并到完全备份中；
[root@mysql17 ~]$innobackupex --apply-log --redo-only /app/backups/2018-02-25_15-21-53/ --incremental-dir=/app/backups/inc2/2018-02-25_15-34-00/
如果数据目录非空，那么就可以删除他；
[root@mysql17 ~]$ls /var/lib/mysql/
将整理后的数据复制到数据目录中；
[root@mysql17 ~]$innobackupex --copy-back /app/backups/2018-02-25_15-21-53/
[root@mysql17 ~]$ll /var/lib/mysql/
total 18444
drwxr-x--- 2 root root 146 Feb 25 02:48 hellodb
-rw-r----- 1 root root 18874368 Feb 25 02:48 ibdata1
drwxr-x--- 2 root root 4096 Feb 25 02:48 mysql
drwxr-x--- 2 root root 4096 Feb 25 02:48 performance_schema
drwxr-x--- 2 root root 20 Feb 25 02:48 test
-rw-r----- 1 root root 481 Feb 25 02:48 xtrabackup_info
[root@mysql17 ~]$
[root@mysql17 ~]$chown -R mysql.mysql /var/lib/mysql/
[root@mysql17 ~]$ll /var/lib/mysql/
total 18444
drwxr-x--- 2 mysql mysql 146 Feb 25 02:48 hellodb
-rw-r----- 1 mysql mysql 18874368 Feb 25 02:48 ibdata1
drwxr-x--- 2 mysql mysql 4096 Feb 25 02:48 mysql
drwxr-x--- 2 mysql mysql 4096 Feb 25 02:48 performance_schema
drwxr-x--- 2 mysql mysql 20 Feb 25 02:48 test
-rw-r----- 1 mysql mysql 481 Feb 25 02:48 xtrabackup_info
[root@mysql17 ~]$启动数据库，核对数据库数据：
[root@mysql17 ~]$systemctl start mariadb
[root@mysql17 ~]$mysql
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 2
Server version: 5.5.56-MariaDB MariaDB Server
Copyright (c) 2000, 2017, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> select * from hellodb.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 | a | 28 | F | NULL | NULL |
| 27 | b | 28 | F | NULL | NULL |
+-------+---------------+-----+--------+---------+-----------+
27 rows in set (0.01 sec)
