Simple disk free monitor shell script :-).

disk-free-mon.sh

#!/bin/bash
#
# @description Simple script which just checks the current state of a mount and then checks the volume for % used. If this % used is > treshold, then it will send an email.
# @author vegaasen
# @since 06.01.2015
# @version 0.1-SNAPSHOT
#
 
THRESHOLD=95;
RECIPIENTS="[email protected]";
PART=u01;
DATE=`date +"Date: %d.%m.%Y - %H:%M:%S"`
IN_USE=`df -h | egrep " " | grep "$PART" | awk '{ print $4 }' | cut -d'%' -f1`;
SERVER_NAME=`uname -n`
SUBJECT="$SERVER_NAME: Disk space warning";
 
if [ $IN_USE -gt $THRESHOLD ]; then
        echo -e "[INFO] The disk for \"$PART\" is above its highest threshold ($IN_USE% > $THRESHOLD%). Sending email to notify: \"$RECIPIENTS\".";
        echo -e "Subject: $SUBJECT\nDisk space warning. The diskspace used is above its threshold levels!\nServername: $SERVER_NAME\nDate sent: $DATE\nDiskspace threshold: $THRESHOLD%\nDiskspace in use: $IN_USE%\nPart: $PART" | sendmail "$RECIPIENTS";
else
        echo -e "$DATE\nCurrent state: OK\nCurrent diskspace-level: $IN_USE%\nCurrent threshold: $THRESHOLD%";
fi