?????????????????
?????????
????mkdir /backup
????chown oracle:oinstall /backup
????chmod 755 /backup
?????????????????
?????? /u01/app/oracle/bin/ ???????on_time_backup.sh???????
??????on_time_backup.sh?????????????????
????#!/bin/bash
????source /home/oracle/.bash_profile
????date=`date +%Y_%m_%d`
????/u01/app/oracle/product/11.2.0/dbhome_1/bin/exp userid=system/oracle@lightingLoan owner=javadeveloping file=/backup/lightingLoan"_"$date.dmp   log=/backup/lightingLoan"_"$date.log
????/usr/bin/find /backup -mtime +7 -exec rm -rf {} ;
???????24?????????  
????crontab -e
????0 24 * * *   /u01/app/oracle/bin/on_time_backup.sh
??????????????backup??
??????root?????? ??????????backup??????????????
????cd /home
????cd /
????ls