'Main entry point when running the reaper in \'once\' mode, where it will
do a single pass over all accounts on the server. This is called
repeatedly by :func:`run_forever`. This will call :func:`reap_device`
once for each device on the server.'

def run_once(self, *args, **kwargs):

    self.logger.debug('Begin    devices    pass:    %s', self.devices)
    begin = time()
    try:
        for device in os.listdir(self.devices):
            if (self.mount_check and (not ismount(os.path.join(self.devices, device)))):
                self.logger.increment('errors')
                self.logger.debug(_('Skipping    %s    as    it    is    not    mounted'), device)
                continue
            self.reap_device(device)
    except (Exception, Timeout):
        self.logger.exception(_('Exception    in    top-level    account    reaper    loop'))
    elapsed = (time() - begin)
    self.logger.info(_('Devices    pass    completed:    %.02fs'), elapsed)
