func resizeServer(t *testing.T, client *gophercloud.ServiceClient, server *servers.Server, choices *ComputeChoices) {
	if err := waitForStatus(client, server, "ACTIVE"); err != nil {
		t.Fatal(err)
	}

	t.Logf("Attempting to resize server [%s]", server.ID)

	opts := &servers.ResizeOpts{
		FlavorRef: choices.FlavorIDResize,
	}
	if res := servers.Resize(client, server.ID, opts); res.Err != nil {
		t.Fatal(res.Err)
	}

	if err := waitForStatus(client, server, "VERIFY_RESIZE"); err != nil {
		t.Fatal(err)
	}
}

//.........这里部分代码省略.........
				log.Printf("[DEBUG] Attempting to disassociate %s from %s", oldFIP, d.Id())
				if err := disassociateFloatingIPFromInstance(computeClient, oldFIP, d.Id(), oldFixedIP); err != nil {
					return fmt.Errorf("Error disassociating Floating IP during update: %s", err)
				}

				log.Printf("[DEBUG] Attempting to associate %s to %s", newFIP, d.Id())
				if err := associateFloatingIPToInstance(computeClient, newFIP, d.Id(), newFixedIP); err != nil {
					return fmt.Errorf("Error associating Floating IP during update: %s", err)
				}
			}
		}
	}

	if d.HasChange("volume") {
		// ensure the volume configuration is correct
		if err := checkVolumeConfig(d); err != nil {
			return err
		}

		// old attachments and new attachments
		oldAttachments, newAttachments := d.GetChange("volume")

		// for each old attachment, detach the volume
		oldAttachmentSet := oldAttachments.(*schema.Set).List()
		if blockClient, err := config.blockStorageV1Client(d.Get("region").(string)); err != nil {
			return err
		} else {
			if err := detachVolumesFromInstance(computeClient, blockClient, d.Id(), oldAttachmentSet); err != nil {
				return err
			}
		}

		// for each new attachment, attach the volume
		newAttachmentSet := newAttachments.(*schema.Set).List()
		if blockClient, err := config.blockStorageV1Client(d.Get("region").(string)); err != nil {
			return err
		} else {
			if err := attachVolumesToInstance(computeClient, blockClient, d.Id(), newAttachmentSet); err != nil {
				return err
			}
		}

		d.SetPartial("volume")
	}

	if d.HasChange("flavor_id") || d.HasChange("flavor_name") {
		flavorId, err := getFlavorID(computeClient, d)
		if err != nil {
			return err
		}
		resizeOpts := &servers.ResizeOpts{
			FlavorRef: flavorId,
		}
		log.Printf("[DEBUG] Resize configuration: %#v", resizeOpts)
		err = servers.Resize(computeClient, d.Id(), resizeOpts).ExtractErr()
		if err != nil {
			return fmt.Errorf("Error resizing OpenStack server: %s", err)
		}

		// Wait for the instance to finish resizing.
		log.Printf("[DEBUG] Waiting for instance (%s) to finish resizing", d.Id())

		stateConf := &resource.StateChangeConf{
			Pending:    []string{"RESIZE"},
			Target:     []string{"VERIFY_RESIZE"},
			Refresh:    ServerV2StateRefreshFunc(computeClient, d.Id()),
			Timeout:    3 * time.Minute,
			Delay:      10 * time.Second,
			MinTimeout: 3 * time.Second,
		}

		_, err = stateConf.WaitForState()
		if err != nil {
			return fmt.Errorf("Error waiting for instance (%s) to resize: %s", d.Id(), err)
		}

		// Confirm resize.
		log.Printf("[DEBUG] Confirming resize")
		err = servers.ConfirmResize(computeClient, d.Id()).ExtractErr()
		if err != nil {
			return fmt.Errorf("Error confirming resize of OpenStack server: %s", err)
		}

		stateConf = &resource.StateChangeConf{
			Pending:    []string{"VERIFY_RESIZE"},
			Target:     []string{"ACTIVE"},
			Refresh:    ServerV2StateRefreshFunc(computeClient, d.Id()),
			Timeout:    3 * time.Minute,
			Delay:      10 * time.Second,
			MinTimeout: 3 * time.Second,
		}

		_, err = stateConf.WaitForState()
		if err != nil {
			return fmt.Errorf("Error waiting for instance (%s) to confirm resize: %s", d.Id(), err)
		}
	}

	return resourceComputeInstanceV2Read(d, meta)
}

// Resize instructs the provider to change the flavor of the server.
// Note that this implies rebuilding it.
// Unfortunately, one cannot pass rebuild parameters to the resize function.
// When the resize completes, the server will be in RESIZE_VERIFY state.
// While in this state, you can explore the use of the new server's configuration.
// If you like it, call ConfirmResize() to commit the resize permanently.
// Otherwise, call RevertResize() to restore the old configuration.
func Resize(client *gophercloud.ServiceClient, id string, opts os.ResizeOptsBuilder) os.ActionResult {
	return os.Resize(client, id, opts)
}