def METHOD_NAME(remoteHost='localhost'):
    """
    Refresh the system caches
    rc=0, drop caches successfully with no warning(s) or error(s)
    rc=1, drop caches successfully with warning(s) but no error(s)
    rc=2, drop caches with error(s), raise TINCSystemException
    @type remoteHost: string
    @param remoteHost: Host name of the machine where drop caches should be executed
    """
    cmdStr = "echo 'echo 3  > /proc/sys/vm/drop_caches' |sudo -s"
    cmd = Command('drop caches', cmdStr, ctxt=REMOTE, remoteHost=remoteHost)
    cmd.run()
    result = cmd.get_results()
    if result.rc > 1:
        msg = "drop caches failed with rc=%s and stderr=%s" % \
                (result.rc, result.stderr)
        tinctest.logger.warning(msg)
        raise TINCSystemException(msg)
    tinctest.logger.info("drop caches success with %s" % result)