可以将这个脚本放进crontab，每天凌晨执行一次，自动备份这个脚本每天最多只执行一次，而且只保留最近五天的备份在服务器上。

　　代码:

#!/bin/bash
#This is a ShellScript For Auto DB Backup
#Powered by SearchDatabase
#2005-09

#Setting
#设置数据库名，数据库登录名，密码，备份路径，日志路径，数据文件位置，以及备份方式
#默认情况下备份方式是tar，还可以是mysqldump,mysqldotcopy
#默认情况下，用root(空)登录mysql数据库，备份至/root/dbxxxxx.tgz
DBName=mysql
DBUser=root
DBPasswd=
BackupPath=/root/
LogFile=/root/db.log
DBPath=/var/lib/mysql/
#BackupMethod=mysqldump
#BackupMethod=mysqlhotcopy
#BackupMethod=tar
#Setting End

NewFile="$BackupPath"db$(date +%y%m%d).tgz
DumpFile="$BackupPath"db$(date +%y%m%d)
OldFile="$BackupPath"db$(date +%y%m%d --date='5 days ago').tgz

echo "-------------------------------------------" >> $LogFile
echo $(date +"%y-%m-%d %H:%M:%S") >> $LogFile
echo "--------------------------" >> $LogFile
#Delete Old File
if [ -f $OldFile ]
then
   rm -f $OldFile >> $LogFile 2>&1
   echo "[$OldFile]Delete Old File Success!" >> $LogFile
else
   echo "[$OldFile]No Old Backup File!" >> $LogFile
fi

if [ -f $NewFile ]
then
   echo "[$NewFile]The Backup File is exists,Can't Backup!" >> $LogFile
else
   case $BackupMethod in
   mysqldump)
      if [ -z $DBPasswd ]
      then
         mysqldump -u $DBUser --opt $DBName > $DumpFile
      else
         mysqldump -u $DBUser -p$DBPasswd --opt $DBName > $DumpFile
      fi
      tar czvf $NewFile $DumpFile >> $LogFile 2>&1
      echo "[$NewFile]Backup Success!" >> $LogFile
      rm -rf $DumpFile
      ;;
   mysqlhotcopy)
      rm -rf $DumpFile
      mkdir $DumpFile
      if [ -z $DBPasswd ]
      then
         mysqlhotcopy -u $DBUser $DBName $DumpFile >> $LogFile 2>&1
      else
         mysqlhotcopy -u $DBUser -p $DBPasswd $DBName $DumpFile >>$LogFile 2>&1
      fi
      tar czvf $NewFile $DumpFile >> $LogFile 2>&1
      echo "[$NewFile]Backup Success!" >> $LogFile
      rm -rf $DumpFile
      ;;
   *)
      /etc/init.d/mysqld stop >/dev/null 2>&1
      tar czvf $NewFile $DBPath$DBName >> $LogFile 2>&1
      /etc/init.d/mysqld start >/dev/null 2>&1
      echo "[$NewFile]Backup Success!" >> $LogFile
      ;;
   esac
fiecho "-------------------------------------------" >> $LogFile