数据是非常重要的，所以数据备份必不可少！比如受到攻击，或者人为误操作时，备份数据就派上用场，及时恢复数据，将影响降到最低。下面以mysql为例，利用mysqldump(mysql自带工具)工具进行备份，实现每天整点定时备份数据库（定时是利用linux的crontab，可以自己配置任意时间），并且只保留7天(时间可配置)

假设数据库名为：test

第一步.创建脚本文件夹

mkdir /usr/local/mysql_backup/dump;

第二步.创建shell脚本

(1)cd mkdir /usr/local/mysql_backup;

(2)vim mysql_backup.sh

内容如下(备份数据库test)：

#!/bin/bash
# 设置mysql登录用户名和密码
mysql_user=""
mysql_password=""
mysql_host=""
mysql_port=""
mysql_charset="utf8mb4"
# 备份存放地址
backup_location=/usr/local/mysql_backup/dump
log_location=/usr/local/mysql_backup/log.log
# 是否删除过期数据
expire_backup_delete="ON"
expire_days=7
backup_time=`date +%Y-%m-%d_%H%M`
backup_dir=$backup_location
welcome_msg="===============into MySQL backup sh================"
# 判断mysql实例是否正常运行
mysql_ps=`ps -ef |grep mysql |wc -l`
mysql_listen=`netstat -an |grep LISTEN |grep $mysql_port|wc -l`
if [ [$mysql_ps == 0] -o [$mysql_listen == 0] ]; then
        echo $(date "+%Y-%m-%d %H:%M:%S") "ERROR:MySQL is not running! backup stop!">> $log_location
        exit
else
        echo $(date "+%Y-%m-%d %H:%M:%S") $welcome_msg>> $log_location
fi
# 备份指定数据库中数据
echo $(date "+%Y-%m-%d %H:%M:%S") "begin dump db test">> $log_location
mysqldump -h$mysql_host -P$mysql_port -u$mysql_user -p$mysql_password -B test> $backup_dir/test_$backup_time.sql
flag=`echo $?`
if [ $flag == "0" ];then
        echo $(date "+%Y-%m-%d %H:%M:%S") "database test success backup">> $log_location
else
        echo $(date "+%Y-%m-%d %H:%M:%S") "database test backup fail!">> $log_location
fi
# 删除过期数据
if [ "$expire_backup_delete" == "ON" -a  "$backup_location" != "" ];then
        `find $backup_location/ -type f -mtime +$expire_days | xargs rm -rf`
        echo $(date "+%Y-%m-%d %H:%M:%S") "Expired backup data delete complete!">> $log_location
fi

第三步.添加定时任务

(1)crontab -e

添加(每个整点执行备份):00 */1 * * * /usr/local/mysql_backup/mysql_backup.sh >> /usr/local/mysql_backup/log.log

(2)service crond restart;

如果需要恢复数据库到某个时间点的话，执行：

mysql -hhost -Pport -uroot -ppassword test< /usr/local/mysql_backup/dump/文件名.sql

效果：

目录