1.先在服务器下建文件夹以下3个文件夹：mkdir /bak,mkdir /bak/bakmysql,mkdir /bak/bakmysqlold 。在/bak/bakmysql文件夹下建一个shell脚本：touch /bak/bakmysql/backup.sh 。给文件授权：chmod 755 /bak/bakmysql/backup.sh 。
2.编辑shell脚本：vi /bak/bakmysql/backup.sh
#!/bin/sh cd /bak/bakmysql echo "You are in bakmysql directory" mv bakmysql* /bak/bakmysqlold echo "Old databases are moved to bakmysqlold folder" Now=$(date +"%d-%m-%Y") File=bakmysql-$Now.sql mysqldump -uroot -p'password' db_bbs > $File echo "Your database backup successfully completed" SevenDays=$(date -d -7day +"%d-%m-%Y") if [ -f /bak/bakmysqlold/bakmysql-$SevenDays.sql ] then rm -rf /bak/bakmysqlold/bakmysql-$SevenDays.sql echo "You have delete 7days ago bak file " else echo "7days ago bak file not exist " fi
3.shell脚本：mysqldump -uroot -p'password' db_bbs> $File 这句中的红色字体请分别换为你自己的mysql数据库用户、密码和database名。脚本先将/bak/bakmysql文件夹下bakmysql为文件名开头的备份文件移至/bak/bakmysqlold，再生成最新的备份文件，最后再判断/bak/bakmysqlold文件夹中七天前的文件是否存在，存在则删除，最后结束。这样就能自动备份最近七天的数据库脚本。
这是博主的服务器截图：
4.设置每天自动执行shell脚本:vi /etc/crontab 在最后加入这样一行（具体含义请自行参考/etc/crontab中的注释）：0 0 * * * root /bak/bakmysql/backup.sh 。重启crontab：/sbin/service crond restart 。如果没有设置crontab为开机自启动可以如下设置其开机自启动：chkconfig –level 35 crond on
