New MD5 based backup script

I found this use of md5 and find the other day. I based my current backup script around it. The md5 will show if anyone modifies a file, or adds/removes a file in the web hosting root (/var/www) or in the config directory (/etc/httpd/conf.d/). If there is a change then zip each site up individually and move to a backup folder to be rsynced to other servers.

NewWWWMD5=$(find /var/www/ -type f -exec md5sum {} \; | md5sum - | awk '{print $1}')
OldWWWMD5=$(cat $PARENTDIR/_var_www_*.md5)
NewConfMD5=$(find /etc/httpd/conf.d/ -type f -exec md5sum {} \; | md5sum - | awk '{print $1}')
OldConfMD5=$(cat $PARENTDIR/_etc_httpd_conf.d_*.md5)

if [ $NewWWWMD5 = $OldWWWMD5 -a $NewConfMD5 = $OldConfMD5 ]; then
	echo "Neither /var/www/ nor /etc/httpd/conf.d/ have changed"
else
	rm -rf $BACKUPDIR/*Files
	echo "/var/www or /etc/httpd/conf.d has changed"
	mkdir -p $BACKUPDIR-Files

	# backup /var/www
	for directory in /var/www/*; do
	  	if [ -d $directory ]; then
	    	bu $directory;
	    fi
	done

	# replace previous /var/www MD5
	rm -f $PARENTDIR/_var_www_*.md5
	find /var/www/ -type f -exec md5sum {} \; | md5sum - | awk '{print $1}' > $PARENTDIR/_var_www_$CURRENTDAY.md5

	#backup /etc/httpd/conf.d
	bu "/etc/httpd/conf.d"

	# replace previous /etc/httpd/conf.d MD5
	rm -f $PARENTDIR/_etc_httpd_conf.d_*.md5
	find /etc/httpd/conf.d/ -type f -exec md5sum {} \; | md5sum - | awk '{print $1}' > $PARENTDIR/_etc_httpd_conf.d_$CURRENTDAY.md5
fi

Seems to work!