mysql备份之lvm

Posted 2021-01-24

新建一个lvm磁盘，这里我建的lv为mydatalv，挂载到了/data下
[[email protected] ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
mydatalv mydata -wi-ao---- 1.00g
[[email protected] ~]# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/mapper/mydata-mydatalv 976M 2.6M 907M 1% /data
将原数据库文件复制到/data目录下
[[email protected] ~]# cp -a /var/lib/mysql /data/
修改配置文件，将mysql数据库文件放在lvm盘中，二进制文件放在非lvm盘的/var/lib/mysql/目录下
[[email protected] ~]# vim /etc/my.cnf
[mysqld]
log_bin=/var/lib/mysql/mysql-bin
datadir=/data/mysql
[[email protected] ~]# service mariadb restart
[[email protected] ~]# ls /data/mysql
aria_log.00000001 ibdata1 ib_logfile1 mysql-bin.000001 mysql-bin.000003 performance_schema
aria_log_control ib_logfile0 mysql mysql-bin.000002 mysql-bin.index test
可以看到重启后数据库文件已存放在了/data/mysql目录中了
对mysql进行锁表备份
[[email protected] ~]# mysql -e ‘flush tables with read lock;‘ 锁表
[[email protected] ~]# mysql -e ‘flush logs;‘ 对日志进行滚动，
[[email protected] ~]# mysql -e ‘show master status;‘ > /root/back.$(date +%F+%T)
[[email protected] ~]# ls
back.2016-07-13+10:14:29
对lv创建快照
[[email protected] ~]# lvcreate -L 1G -n mysqlback -p r -s /dev/mydata/mydatalv
释放锁
[[email protected] ~]# mysql -e ‘unlock tables;‘
在别的磁盘上创建备份目录，只读挂载快照后备份至备份目录
[[email protected] ~]# mkdir /myback
[[email protected] ~]# mount -r /dev/mydata/mysqlback /mnt
[[email protected] ~]# cp -a /mnt/mysql /myback
修改表内容，然后删除掉数据库文件内容即/data/mysql中的内容
[[email protected] ~]# mysql
MariaDB [hellodb]> use hellodb;
MariaDB [hellodb]> insert into classes (class,numofstu) values (‘xxoo‘,39);
[[email protected] ~]# rm -rf /data/*
修改配置文件中二进制日志和数据库文件的位置
[[email protected] ~]# vim /etc/my.cnf
[mysqld]
log_bin=/data/mysql/mysql-bin
datadir=/data/mysql 利用/myback/中的内容还原

[[email protected] ~]# cp -a /myback/ /data/
[[email protected] ~]# service mariadb restart
利用二进制日志还原快照后的操作，由下面这个文件来查看快照执行时二进制日志的位置
[[email protected] ~]# cat back.2016-07-13+10:14:29
File Position Binlog_Do_DB Binlog_Ignore_DB
mysql-bin.000014 245
将000014中245之后的操作做成sql文件，进行还原
[[email protected] ~]# mysqlbinlog --start-position=245 /var/lib/mysql/mysql-bin.000014 > binlog.sql
[[email protected] ~]# mysql < /root/binlog.sql
查看恢复情况
[[email protected] ~]# mysql
MariaDB [(none)]> use hellodb;
MariaDB [hellodb]> select from classes;
+---------+----------------+----------+
| ClassID | Class | NumOfStu |
+---------+----------------+----------+
| 1 | Shaolin Pai | 10 |
| 2 | Emei Pai | 7 |
| 3 | QingCheng Pai | 11 |
| 4 | Wudang Pai | 12 |
| 5 | Riyue Shenjiao | 31 |
| 6 | Lianshan Pai | 27 |
| 7 | Ming Jiao | 27 |
| 8 | Xiaoyao Pai | 15 |
| 9 | xxoo | 39 |
+---------+----------------+----------+
9 rows in set (0.00 sec)