def get_sys_meta_prefix(server_type):
    """
    Returns the prefix for system metadata headers for given server type.

    This prefix defines the namespace for headers that will be persisted
    by backend servers.

    :param server_type: type of backend server i.e. [account|container|object]
    :returns: prefix string for server type's system metadata headers
    """
    return 'x-%s-%s-' % (server_type.lower(), 'sysmeta')