Few updated needed on the new version

The script is really good.

Just few updated needed:

as the new version is using vmstat and not iostat, so it would be nice to check vmstat:

here is my modification:

#IOSTAT=/usr/bin/iostat
VMSTAT=/usr/bin/vmstat

and the check:

# if [ ! -x $IOSTAT ]; then
if [ ! -x $VMSTAT ]; then
# echo “UNKNOWN: iostat not found or is not executable by the nagios user.”
echo “UNKNOWN: vmstat not found or is not executable by the nagios user.”
exit $STATE_UNKNOWN
fi