'Starts sar subprocess.
:param test: Autotest test on which this profiler will operate on.'

def start(self, test):

    logfile = open(os.path.join(test.profdir, 'sar'), 'w')
    raw = os.path.join(test.profdir, 'sar.raw')
    cmd = (self.cmd % (raw, self.interval))
    self.sar_process = subprocess.Popen(cmd, shell=True, stdout=logfile, stderr=subprocess.STDOUT)
