Configures the host cahe of the specified host

    host_ref
        The vim.HostSystem object representing the host that contains the
        requested disks.

    datastore_ref
        The vim.Datastore opject representing the datastore the host cache will
        be configured on.

    swap_size_MiB
        The size in Mibibytes of the swap.

    host_cache_manager
        The vim.HostCacheConfigurationManager object representing the cache
        configuration manager on the specified host. Default is None. If None,
        it will be retrieved in the method

def configure_host_cache(host_ref, datastore_ref, swap_size_MiB,
                         host_cache_manager=None):
    '''
    Configures the host cahe of the specified host

    host_ref
        The vim.HostSystem object representing the host that contains the
        requested disks.

    datastore_ref
        The vim.Datastore opject representing the datastore the host cache will
        be configured on.

    swap_size_MiB
        The size in Mibibytes of the swap.

    host_cache_manager
        The vim.HostCacheConfigurationManager object representing the cache
        configuration manager on the specified host. Default is None. If None,
        it will be retrieved in the method
    '''
    hostname = get_managed_object_name(host_ref)
    if not host_cache_manager:
        props = get_properties_of_managed_object(
            host_ref, ['configManager.cacheConfigurationManager'])
        if not props.get('configManager.cacheConfigurationManager'):
            raise salt.exceptions.VMwareObjectRetrievalError(
                'Host \'{0}\' has no host cache'.format(hostname))
        host_cache_manager = props['configManager.cacheConfigurationManager']
    log.trace('Configuring the host cache on host \'%s\', datastore \'%s\', '
              'swap size=%s MiB', hostname, datastore_ref.name, swap_size_MiB)

    spec = vim.HostCacheConfigurationSpec(
        datastore=datastore_ref,
        swapSize=swap_size_MiB)
    log.trace('host_cache_spec=%s', spec)
    try:
        task = host_cache_manager.ConfigureHostCache_Task(spec)
    except vim.fault.NoPermission as exc:
        log.exception(exc)
        raise salt.exceptions.VMwareApiError(
            'Not enough permissions. Required privilege: '
            '{0}'.format(exc.privilegeId))
    except vim.fault.VimFault as exc:
        log.exception(exc)
        raise salt.exceptions.VMwareApiError(exc.msg)
    except vmodl.RuntimeFault as exc:
        log.exception(exc)
        raise salt.exceptions.VMwareRuntimeError(exc.msg)
    wait_for_task(task, hostname, 'HostCacheConfigurationTask')
    log.trace('Configured host cache on host \'%s\'', hostname)
    return True