#!/bin/bash
# $Id: fsusage 470 2004-12-09 16:56:11Z agriffis $
#
# Copyright 2004 Aron Griffis
# Released under the GNU GPL v2
#
# fsusage: check filesystem usage and issue a warning to syslog if necessary
# 

PATH=/usr/bin:/bin:/usr/sbin:/sbin

# percentage to warn at; defaults to 90
warnlevel=${1:-90}

# persistent storage area
fsudir=/var/lib/fsusage

# logging function
log() {
    logger -p local0.alert -t fsusage -- "$1"
}

mkdir -p $fsudir || {
    log "failed to create $fsudir"
    exit 1
}

# check local filesystems only
df -lh | grep '^/' | while read l; do
    set -- $l
    fs=$1
    total=$2
    used=$3
    pct=${5%\%}
    mnt=$6
    statefile=$fsudir/usage${fs//\//_}

    if [[ $mnt == /mnt/* ]]; then
        continue
    fi

    if [[ $pct -eq 100 ]]; then
        log "warning: $mnt is RED at $pct% ($used of $total used)"
        echo $pct > $statefile

    elif [[ $pct -ge $warnlevel ]]; then
        log "warning: $mnt is YELLOW at $pct% ($used of $total used)"
        echo $pct > $statefile

    elif [[ -r $statefile && $(<$statefile) -ge $warnlevel ]]; then
        log "info: $mnt is GREEN at $pct% ($used of $total used)"
        rm -f $statefile
    fi
done