#!/bin/bash
THRESHOLD=90

df -PkH | grep '/opt/backups' | awk '{ print $5 " " $6 }' | while read output;
do
    usep=$(echo $output | awk '{ print $1}' | cut -d'%' -f1 )
    partition=$(echo $output | awk '{print $2}' )
    if [ $usep -ge $THRESHOLD ]; then
        echo "Backup volume \"$partition ($usep%)\" on $(hostname) at $(date)" |
            mail -s "ACTION REQUIRED: Backup volume usage at $usep%" infra-root@openstack.org
    fi
done