根據要求寫下MySQL備份腳本，要求如下：對指定數據庫進行日備份并且將備份文件保存一周，對一周以外文件自動刪除。

1、創建shell腳本
[root@server18 mysql]$ mkdir -p /home/mysql/DB_BAK/day_bak/

DB_NAME='tdc_ntt_debug'
USER='mysql'
PWD='mysql'
TIME=$(date +%Y%m%d)
DEL_TIME=$(date --date="7 days ago" +%Y%m%d)
DB_BAK_NAME=tdc_debug${TIME}.sql
DB_DEL_NAME=tdc_debug${DEL_TIME}.sql
BACKUP_PATH='/home/mysql/DB_BAK/day_bak/'
echo $BACKUP_PATH$DB_BAK_NAME
if test -f $BACKUP_PATH$DB_DEL_NAME
    then
        echo "Delete history dump file"
        rm -f $BACKUP_PATH$DB_DEL_NAME
fi
mysqldump -u $USER -p$PWD $DB_NAME > $BACKUP_PATH$DB_BAK_NAME
2.修改計劃任務/etc/crontab

[root@server18 ~]# crontab -e

30 21 * * * root /home/mysql/DB_BAK/day_bak/day_bak.sh

每天晚上21：30進行MySQL備份，將備份文件保留7天。