myc-manage/etc/cron.hourly/disk_usage

#!/bin/bash

SHELL=/bin/bash
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin

## check disk usage and send a notification if it's above 75% or 90%

percent_usage=$(df /srv -h)
percent_usage=${percent_usage##*$'\n'}
percent_usage=${percent_usage% *}
percent_usage=${percent_usage##* }
percent_usage=${percent_usage%\%}

LOCK_WORKING_DIR="/var/run/myc-manage"
mkdir -p "$LOCK_WORKING_DIR"

if [ "$percent_usage" -ge "90" ]; then
   if [ -e $LOCK_WORKING_DIR/disk_usage_90.lock ]; then
      exit 0
   else
      touch $LOCK_WORKING_DIR/disk_usage_90.lock
      message="[$(hostname)]: WARNING disk usage >=90%"
      send "$message"
   fi
elif [ "$percent_usage" -ge "75" ]; then
   if [ -e $LOCK_WORKING_DIR/disk_usage_75.lock ]; then
      exit 0
   else
      touch $LOCK_WORKING_DIR/disk_usage_75.lock
      message="[$(hostname)]: WARNING disk usage >=75 <90%"
      send "$message"
   fi
else
   if [ -e $LOCK_WORKING_DIR/disk_usage_75.lock ]; then
      rm $LOCK_WORKING_DIR/disk_usage_75.lock
   fi
   if [ -e $LOCK_WORKING_DIR/disk_usage_90.lock ]; then
      rm $LOCK_WORKING_DIR/disk_usage_90.lock
   fi
fi