完全和差分备份的自动化模型

下面提供了一个简单的脚本文件来作为一个同时实现完全和差分备份的自动化模型。在使用该脚本以前，请注意检查脚本头定义的环境变量以满足自己的需要。

#!/bin/sh
　　#
　　#######################################
　　#
　　# TAR backup script to cover daily and weekly backups on one tape.
　　# Generic UNIX version - edit variables as required
　　#
　　# For this to work, it MUST be started on a Monday!
　　#
　　# Copyright (c) 1999, Tim Jones
　　# Permission granted for use/modification
　　#
　　# Tim Jones/Linux Magazine provide this shell script with no warranty
　　# (implied or otherwise)
　　#
　　########################################

　　DOW=`date +%w`
　　DATE=`date +%D`
　　DAY=`date +%A`
　　DEVICE="MY REWIND TAPE" # Rewinding tape drive
　　NDEVICE="MY NO_REWIND TAPE" # non-rewinding tape drive
　　REWIND="mt -f $DEVICE rewind"
　　EOD="mt -f $NDEVICE eod"
　　FSF="mt -f $NDEVICE fsf"
　　MAILLIST="root" # list of users to receive backup notice

　　if [ $DOW = "6" ]
　　then
　　# This is Saturday, so append and write the whole system!
　　$EOD
　　echo $DATE > /tmp/.LASTFULL
　　tar -cvvf $NDEVICE / >/tmp/backup.txt
　　$REWIND
　　$FSF 5
　　tar -dvf $NDEVICE >> /tmp/backup.txt
　　$REWIND
　　cp /tmp/.LASTFULL /etc/.LASTFULL
　　else
　　# this is not Saturday
　　case $DOW in
　　0)
　　# it's Sunday - nothing to do
　　exit 0
　　;;
　　1)
　　# Monday, Let the tape rewind for the difference verification
　　echo $DATE > /tmp/.LASTINC
　　tar -cvvf $DEVICE --newer `cat /etc/.LASTFULL` / >/tmp/backup.txt
　　cp /tmp/.LASTINC /etc/.LASTINC
　　;;
　　*)
　　# Other Days, must rewind manually and Inspect, -i
　　$EOD
　　echo $DATE >/tmp/.LASTINC
　　tar -cvvf $NDEVICE --newer `cat /etc/.LASTINC` / >/tmp/backup
　　$REWIND
　　$FSF `expr $DOW - 1`
　　echo "************ Verifying ${DAY}'s backup" >> /tmp/backup.txt
　　tar --dvf $NDEVICE >> /tmp/backup.txt
　　cp /tmp/.LASTINC /etc/.LASTINC
　　$REWIND
　　esac
　　fi
　　mail $MAILLIST < /tmp/backup.txt
　　rm -f /tmp/backup.txt
　　# END OF SCRIPT