Controlar la carga de un sistema Unix

Navegando por internet me encontré con un script que nos puede ser de mucha utilidad si queremos controla el estado de carga de un sistema Unix. En caso de que la carga del sistema sobrepase un determinado límite, el script mandará un email al administrador del sistema para notificarle dicha alerta.

#!/bin/bash
#
# Script to notify admin user if Linux,FreeBSD load crossed certain limit
# It will send an email notification to admin.
#
# Copyright 2005 (c) nixCraft project
# This is free script under GNU GPL version 2.0 or above.
# Support/FeedBack/comment :  http://cyberciti.biz/fb/
# Tested os:
# * RedHat Linux
# * Debain Linux
# * FreeBSD
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------
 
# Set up limit below
NOTIFY="6.0"
 
# admin user email id
EMAIL="root"
 
# Subject for email
SUBJECT="Alert $(hostname) load average"
 
# -----------------------------------------------------------------
 
# Os Specifc tweaks do not change anything below ;)
OS="$(uname)"
TRUE="1"
if [ "$OS" == "FreeBSD" ]; then
        TEMPFILE="$(mktemp /tmp/$(basename $0).tmp.XXX)"
	FTEXT='load averages:'
elif [ "$OS" == "Linux" ]; then
        TEMPFILE="$(mktemp)"
	FTEXT='load average:'
fi
 
# get first 5 min load
F5M="$(uptime | awk -F "$FTEXT" '{ print $2 }' | cut -d, -f1) | sed 's/ //g'"
# 10 min
F10M="$(uptime | awk -F "$FTEXT" '{ print $2 }' | cut -d, -f2) | sed 's/ //g'"
# 15 min
F15M="$(uptime | awk -F "$FTEXT" '{ print $2 }' | cut -d, -f3) | sed 's/ //g'"
 
# mail message
# keep it short coz we may send it to page or as an short message (SMS)
echo "Load average Crossed allowed limit $NOTIFY." >> $TEMPFILE
echo "Hostname: $(hostname)" >> $TEMPFILE
echo "Local Date & Time : $(date)" >> $TEMPFILE
 
# Look if it crossed limit
# compare it with last 15 min load average
RESULT=$(echo "$F15M > $NOTIFY" | bc)
 
# if so send an email
if [ "$RESULT" == "$TRUE" ]; then
        mail -s "$SUBJECT" "$EMAIL" < $TEMPFILE
fi
 
# remove file
rm -f $TEMPFILE

Si quereis revisar el script (con las últimas actualizaciones), podéis encontrarlo en bash.cyberciti.biz