Create custom images


You can create custom images from source disks, images, snapshots, or images stored in Cloud Storage and use these images to create virtual machine (VM) instances. Custom images are ideal for situations where you have created and modified a persistent boot disk or specific image to a certain state and need to save that state for creating VMs.

Alternatively, you can use the virtual disk import tool to import boot disk images to Compute Engine from your existing systems and add them to your custom images list.

Before you begin

Create a custom image

This section describes how to create a custom image on a Linux VM. For information about creating a Windows image, see Creating a Windows image.

Select an image storage location

When creating a custom image, you can specify the image's Cloud Storage location, excluding dual-region locations. By specifying the image storage location, you can meet your regulatory and compliance requirements for data locality as well as your high availability needs by ensuring redundancy across regions. To create, modify, and delete images stored in Cloud Storage, you must have roles/compute.storageAdmin.

The storage location feature is optional. If you don't select a location, Compute Engine stores your image in the multi-region closest to the image source. For example, when you create an image from a source disk that is located in us-central1 and if you don't specify a location for the custom image, then Compute Engine stores the image in the us multi-region.

If the image is not available in a region where you are creating a VM, Compute Engine caches the image in that region the first time you create a VM.

To see the location where an image is stored, use the images describe command from gcloud compute:

gcloud compute images describe IMAGE_NAME \
    --project=PROJECT_ID

Replace the following:

  • IMAGE_NAME: the name of your image.

  • PROJECT_ID: the project ID to which the image belongs.

All of your existing images prior to this feature launch remain where they are, the only change is that you can view the image location of all your images. If you have an existing image you want to move, you must recreate it in the desired location.

Prepare your VM for an image

You can create an image from a disk even while it is attached to a running VM. However, your image is more reliable if you put the VM in a state that is easier for the image to capture. This section describes how to prepare your boot disk for the image.

Minimize writing data to the persistent disk

Use one of the following processes to reduce the disk writes:

  • Stop the VM so that it can shut down and stop writing any data to the persistent disk.

  • If you can't stop your VM before you create the image, minimize the amount of writes to the disk and sync your file system. To minimize writing to your persistent disk, follow these steps:

    1. Pause apps or operating system processes that write data to that persistent disk.
    2. Run an app flush to disk if necessary. For example, MySQL has a FLUSH statement. Other apps might have similar processes.
    3. Stop your apps from writing to your persistent disk.
    4. Run sudo sync.

Disable the auto-delete option for the disk

By default, the auto-delete option is enabled on the boot disks. Before creating an image from a disk, disable auto-delete to ensure that the disk is not automatically deleted when you delete the VM.

You can use the Google Cloud console, the Google Cloud CLI, or the Compute Engine API to disable auto-delete for the disk.

Console

  1. In the Google Cloud console, go to the VM instances page.

    Go to the VM instances page

  2. Click on the VM that you're using as the source for creating an image. The VM instance details page displays.

  3. Click Edit.

  4. In the Boot disk section, for the Deletion rule, ensure that the Keep disk option is selected.

  5. Click Save.

gcloud

In the Google Cloud CLI, use the gcloud compute instances set-disk-auto-delete command to disable the auto-delete option for the disk.

gcloud compute instances set-disk-auto-delete VM_NAME \
    --no-auto-delete \
    --disk=SOURCE_DISK

Replace the following:

  • VM_NAME: the name of your VM instance.
  • SOURCE_DISK: the name of the disk from which you want to create the image.

API

To set the auto-delete option of a disk, make a POST request to the instances.setDiskAutoDelete method.

POST https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/zones/ZONE/instances/VM_NAME/setDiskAutoDelete?autoDelete=false&deviceName=SOURCE_DISK

Replace the following:

  • PROJECT_ID: the project ID to which the source VM belongs.
  • ZONE: the zone where the source VM is located.
  • VM_NAME: the name of the source VM.
  • SOURCE_DISK: the device name of the disk from which you want to create the image.

Go

Go

Before trying this sample, follow the Go setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Go API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import (
	"context"
	"fmt"
	"io"

	compute "cloud.google.com/go/compute/apiv1"
	computepb "google.golang.org/genproto/googleapis/cloud/compute/v1"
)

// setDiskAutodelete sets the autodelete flag of a disk to given value.
func setDiskAutoDelete(
	w io.Writer,
	projectID, zone, instanceName, diskName string, autoDelete bool,
) error {
	// projectID := "your_project_id"
	// zone := "us-west3-b"
	// instanceName := "your_instance_name"
	// diskName := "your_disk_name"
	// autoDelete := true

	ctx := context.Background()
	instancesClient, err := compute.NewInstancesRESTClient(ctx)
	if err != nil {
		return fmt.Errorf("NewInstancesRESTClient: %w", err)
	}
	defer instancesClient.Close()

	getInstanceReq := &computepb.GetInstanceRequest{
		Project:  projectID,
		Zone:     zone,
		Instance: instanceName,
	}

	instance, err := instancesClient.Get(ctx, getInstanceReq)
	if err != nil {
		return fmt.Errorf("unable to get instance: %w", err)
	}

	diskExists := false

	for _, disk := range instance.GetDisks() {
		if disk.GetDeviceName() == diskName {
			diskExists = true
			break
		}
	}

	if !diskExists {
		return fmt.Errorf(
			"instance %s doesn't have a disk named %s attached",
			instanceName,
			diskName,
		)
	}

	req := &computepb.SetDiskAutoDeleteInstanceRequest{
		Project:    projectID,
		Zone:       zone,
		Instance:   instanceName,
		DeviceName: diskName,
		AutoDelete: autoDelete,
	}

	op, err := instancesClient.SetDiskAutoDelete(ctx, req)
	if err != nil {
		return fmt.Errorf("unable to set disk autodelete field: %w", err)
	}

	if err = op.Wait(ctx); err != nil {
		return fmt.Errorf("unable to wait for the operation: %w", err)
	}

	fmt.Fprintf(w, "disk autoDelete field updated.\n")

	return nil
}

Java

Java

Before trying this sample, follow the Java setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Java API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.


import com.google.cloud.compute.v1.Instance;
import com.google.cloud.compute.v1.InstancesClient;
import com.google.cloud.compute.v1.Operation;
import com.google.cloud.compute.v1.SetDiskAutoDeleteInstanceRequest;
import java.io.IOException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class SetDiskAutodelete {

  public static void main(String[] args)
      throws IOException, ExecutionException, InterruptedException, TimeoutException {
    // TODO(developer): Replace these variables before running the sample.

    // Project ID or project number of the Cloud project you want to use.
    String projectId = "YOUR_PROJECT_ID";

    // The zone of the disk that you want to modify.
    String zone = "europe-central2-b";

    // Name of the instance the disk is attached to.
    String instanceName = "YOUR_INSTANCE_NAME";

    // The name of the disk for which you want to modify the autodelete flag.
    String diskName = "YOUR_DISK_NAME";

    // The new value of the autodelete flag.
    boolean autoDelete = true;

    setDiskAutodelete(projectId, zone, instanceName, diskName, autoDelete);
  }

  // Sets the autodelete flag of a disk to given value.
  public static void setDiskAutodelete(String projectId, String zone, String instanceName,
      String diskName, boolean autoDelete)
      throws IOException, ExecutionException, InterruptedException, TimeoutException {

    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the `instancesClient.close()` method on the client to safely
    // clean up any remaining background resources.
    try (InstancesClient instancesClient = InstancesClient.create()) {

      // Retrieve the instance given by the instanceName.
      Instance instance = instancesClient.get(projectId, zone, instanceName);

      // Check if the instance contains a disk that matches the given diskName.
      boolean diskNameMatch = instance.getDisksList()
          .stream()
          .anyMatch(disk -> disk.getDeviceName().equals(diskName));

      if (!diskNameMatch) {
        throw new Error(
            String.format("Instance %s doesn't have a disk named %s attached", instanceName,
                diskName));
      }

      // Create the request object.
      SetDiskAutoDeleteInstanceRequest request = SetDiskAutoDeleteInstanceRequest.newBuilder()
          .setProject(projectId)
          .setZone(zone)
          .setInstance(instanceName)
          .setDeviceName(diskName)
          // Update the autodelete property.
          .setAutoDelete(autoDelete)
          .build();

      // Wait for the update instance operation to complete.
      Operation response = instancesClient.setDiskAutoDeleteAsync(request)
          .get(3, TimeUnit.MINUTES);

      if (response.hasError()) {
        System.out.println("Failed to update Disk autodelete field!" + response);
        return;
      }
      System.out.println(
          "Disk autodelete field updated. Operation Status: " + response.getStatus());
    }
  }
}

Node.js

Node.js

Before trying this sample, follow the Node.js setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Node.js API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

/**
 * TODO(developer): Uncomment and replace these variables before running the sample.
 */
// const projectId = 'YOUR_PROJECT_ID';
// const zone = 'europe-central2-b';
// const instanceName = 'YOUR_INSTANCE_NAME';
// const diskName = 'YOUR_DISK_NAME';
// const autoDelete = true;

const compute = require('@google-cloud/compute');

async function setDiskAutodelete() {
  const instancesClient = new compute.InstancesClient();

  const [instance] = await instancesClient.get({
    project: projectId,
    zone,
    instance: instanceName,
  });

  if (!instance.disks.some(disk => disk.deviceName === diskName)) {
    throw new Error(
      `Instance ${instanceName} doesn't have a disk named ${diskName} attached.`
    );
  }

  const [response] = await instancesClient.setDiskAutoDelete({
    project: projectId,
    zone,
    instance: instanceName,
    deviceName: diskName,
    autoDelete,
  });
  let operation = response.latestResponse;
  const operationsClient = new compute.ZoneOperationsClient();

  // Wait for the update instance operation to complete.
  while (operation.status !== 'DONE') {
    [operation] = await operationsClient.wait({
      operation: operation.name,
      project: projectId,
      zone: operation.zone.split('/').pop(),
    });
  }

  console.log('Disk autoDelete field updated.');
}

setDiskAutodelete();

Python

Python

Before trying this sample, follow the Python setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Python API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

from __future__ import annotations

import sys
from typing import Any

from google.api_core.extended_operation import ExtendedOperation
from google.cloud import compute_v1


def wait_for_extended_operation(
    operation: ExtendedOperation, verbose_name: str = "operation", timeout: int = 300
) -> Any:
    """
    Waits for the extended (long-running) operation to complete.

    If the operation is successful, it will return its result.
    If the operation ends with an error, an exception will be raised.
    If there were any warnings during the execution of the operation
    they will be printed to sys.stderr.

    Args:
        operation: a long-running operation you want to wait on.
        verbose_name: (optional) a more verbose name of the operation,
            used only during error and warning reporting.
        timeout: how long (in seconds) to wait for operation to finish.
            If None, wait indefinitely.

    Returns:
        Whatever the operation.result() returns.

    Raises:
        This method will raise the exception received from `operation.exception()`
        or RuntimeError if there is no exception set, but there is an `error_code`
        set for the `operation`.

        In case of an operation taking longer than `timeout` seconds to complete,
        a `concurrent.futures.TimeoutError` will be raised.
    """
    result = operation.result(timeout=timeout)

    if operation.error_code:
        print(
            f"Error during {verbose_name}: [Code: {operation.error_code}]: {operation.error_message}",
            file=sys.stderr,
            flush=True,
        )
        print(f"Operation ID: {operation.name}", file=sys.stderr, flush=True)
        raise operation.exception() or RuntimeError(operation.error_message)

    if operation.warnings:
        print(f"Warnings during {verbose_name}:\n", file=sys.stderr, flush=True)
        for warning in operation.warnings:
            print(f" - {warning.code}: {warning.message}", file=sys.stderr, flush=True)

    return result


def set_disk_autodelete(
    project_id: str, zone: str, instance_name: str, disk_name: str, autodelete: bool
) -> None:
    """
    Set the autodelete flag of a disk to given value.

    Args:
        project_id: project ID or project number of the Cloud project you want to use.
        zone: name of the zone in which is the disk you want to modify.
        instance_name: name of the instance the disk is attached to.
        disk_name: the name of the disk which flag you want to modify.
        autodelete: the new value of the autodelete flag.
    """
    instance_client = compute_v1.InstancesClient()
    instance = instance_client.get(
        project=project_id, zone=zone, instance=instance_name
    )

    for disk in instance.disks:
        if disk.device_name == disk_name:
            break
    else:
        raise RuntimeError(
            f"Instance {instance_name} doesn't have a disk named {disk_name} attached."
        )

    disk.auto_delete = autodelete

    operation = instance_client.update(
        project=project_id,
        zone=zone,
        instance=instance_name,
        instance_resource=instance,
    )

    wait_for_extended_operation(operation, "disk update")

After you prepare the VM, create the image.

Create the image

You can create disk images from the following sources:

  • A persistent disk, even while that disk is attached to a VM
  • A snapshot of a persistent disk
  • Another image in your project
  • An image that is shared from another project
  • A compressed RAW image in Cloud Storage

You can create a disk image once every 10 minutes. If you want to issue a burst of requests to create a disk image, you can issue at most 6 requests in 60 minutes. For more information, see Snapshot frequency limits.

Console

  1. In the Google Cloud console, go to the Create an image page.

    Go to Create an image

  2. Specify the Name of your image.

  3. Specify the Source from which you want to create an image. This can be a persistent disk, a snapshot, another image, or a disk.raw file in Cloud Storage.

  4. If you are creating an image from a disk attached to a running VM, check Keep instance running to confirm that you want to create the image while the VM is running. You can prepare your VM before creating the image.

  5. In the Based on source disk location (default) drop-down list, specify the location to store the image. For example, specify us to store the image in the us multi-region, or us-central1 to store it in the us-central1 region. If you don't make a selection, Compute Engine stores the image in the multi-region closest to your image's source location.

  6. Optional: specify the properties for your image.

    • Family: the image family this new image belongs to.
    • Description: a description for your custom image.
    • Label: a label to group together resources.
  7. Specify the encryption key. You can choose between a Google-managed key, a Cloud Key Management Service (Cloud KMS) key or a customer- supplied encryption (CSEK) key. If no encryption key is specified, images are encrypted using a Google-managed key.

  8. Click Create to create the image.

gcloud

In the Google Cloud CLI, use the gcloud compute images create command to create a custom image.

Create an image from a source disk:

The --force flag is an optional flag that lets you create the image from a running instance. By default, you cannot create images from running instances. Specify this flag only if you are sure that you want to create the image while the instance is running.

gcloud compute images create IMAGE_NAME \
    --source-disk=SOURCE_DISK \
    --source-disk-zone=ZONE \
    [--family=IMAGE_FAMILY] \
    [--storage-location=LOCATION] \
    [--force]

Replace the following:

  • IMAGE_NAME: a name for the new image
  • SOURCE_DISK: the disk from which you want to create the image
  • ZONE: the zone where the disk is located
  • IMAGE_FAMILY: Optional: a flag that specifies which image family this image belongs to
  • LOCATION: Optional: a flag that lets you designate the region or multi-region where your image is stored. For example, specify us to store the image in the us multi-region, or us-central1 to store it in the us-central1 region. If you don't make a selection, Compute Engine stores the image in the multi-region closest to your image's source location.

Create an image from a source image:

gcloud compute images create IMAGE_NAME \
  --source-image=SOURCE_IMAGE \
  [--source-image-project=IMAGE_PROJECT] \
  [--family=IMAGE_FAMILY] \
  [--storage-location=LOCATION]

Replace the following:

  • IMAGE_NAME: a name for the new image.
  • SOURCE_IMAGE: the image from which you want to create the new image.
  • IMAGE_PROJECT: Optional: the project the source image is located in. Use this parameter if you want to copy an image from another project.
  • IMAGE_FAMILY: Optional: the image family this new image belongs to.
  • LOCATION: Optional: lets you designate the region or multi-region where your image is stored. For example, specify us to store the image in the us multi-region, or us-central1 to store it in the us-central1 region. If you do not make a selection, Compute Engine stores the image in the multi-region closest to your image's source location.

Create an image from a snapshot:

gcloud compute images create IMAGE_NAME \
    --source-snapshot=SOURCE_SNAPSHOT \
    [--storage-location=LOCATION]

Replace the following:

  • IMAGE_NAME: a name for the new image
  • SOURCE_SNAPSHOT: the snapshot from which you want to create the image
  • LOCATION: Optional: a flag that lets you designate the region or multi-region where your image is stored. For example, specify us to store the image in the us multi-region, or us-central1 to store it in the us-central1 region. If you don't make a selection, Compute Engine stores the image in the multi-region closest to your image's source location.

View an image location:

Use the gcloud compute images describe command to view an image location.

gcloud compute images describe IMAGE_NAME

Replace IMAGE_NAME with the name of your image that you want to review.

API

Make a POST request to the images().insert method, a URL in the request body that points to the source object from which you want to create the image. Specify URLs to your resources using your own project ID and resource names.

Create an image from a persistent disk:

POST https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/global/images

{
  "name": "IMAGE_NAME",
  "sourceDisk": "/zones/ZONE/disks/SOURCE_DISK",
  ("storageLocations": "LOCATION",)
  ("forceCreate": "TRUE")
}

Replace the following:

  • PROJECT_ID: the project ID to which the image belongs.
  • IMAGE_NAME: a name for the new image that you want to create.
  • ZONE: the zone where the source disk is located.
  • SOURCE_DISK: the disk from which you want to create the image.
  • LOCATION: Optional: the storage location of your image. For example, specify us to store the image in the us multi-region, or us-central1 to store it in the us-central1 region. If you don't make a selection, Compute Engine stores the image in the multi-region closest to your image's source location.

The optional forceCreate parameter lets you create the image from a running VM. Specify TRUE only if you are sure that you want to create the image from a running VM. The forceCreate default setting is FALSE.

Create an image from another image:

POST https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/global/images

{
  "name": "IMAGE_NAME",
  "sourceImage": "/global/images/SOURCE_IMAGE",
  ("storageLocations": "LOCATION")
}

Replace the following:

  • PROJECT_ID: the project to which the image belongs.
  • IMAGE_NAME: a name for the new image that you want to create.
  • SOURCE_IMAGE: the image from which you want to create the image.
  • LOCATION: Optional: the storage location of your image. For example, specify us to store the image in the us multi-region, or us-central1 to store it in the us-central1 region. If you do not make a selection, Compute Engine stores the image in the multi-region closest to your image's source location.

Create an image from a snapshot:

POST https://compute.googleapis.com/compute/v1/projects/PROJECT_ID/global/images
{
  "name": "IMAGE_NAME",
  "sourceSnapshot": "(/SOURCE_PROJECT_ID)/global/snapshots/SOURCE_SNAPSHOT",
  ("storageLocations": "LOCATION")
}

Replace the following:

  • PROJECT_ID: the project to which the image belongs.
  • IMAGE_NAME: a name for the new image that you want to create.
  • SOURCE_PROJECT_ID: Optional: the project the snapshot is located in. You must have permission to access the snapshot resource in that project.
  • SOURCE_SNAPSHOT: the snapshot from which you want to create the image.
  • LOCATION: Optional: the storage location of your image. For example, specify us to store the image in the us multi-region, or us-central1 to store it in the us-central1 region. If you do not make a selection, Compute Engine stores the image in the multi-region closest to your image's source location.

Go

Go

Before trying this sample, follow the Go setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Go API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import (
	"context"
	"fmt"
	"io"

	compute "cloud.google.com/go/compute/apiv1"
	computepb "google.golang.org/genproto/googleapis/cloud/compute/v1"
)

// Creates a disk image from an existing disk
func createImageFromDisk(
	w io.Writer,
	projectID, zone, sourceDiskName, imageName string,
	storageLocations []string,
	forceCreate bool,
) error {
	// projectID := "your_project_id"
	// zone := "us-central1-a"
	// sourceDiskName := "your_disk_name"
	// imageName := "my_image"
	// // If storageLocations empty, automatically selects the closest one to the source
	// storageLocations = []string{}
	// // If forceCreate is set to `true`, proceeds even if the disk is attached to
	// // a running instance. This may compromise integrity of the image!
	// forceCreate = false

	ctx := context.Background()
	disksClient, err := compute.NewDisksRESTClient(ctx)
	if err != nil {
		return fmt.Errorf("NewDisksRESTClient: %w", err)
	}
	defer disksClient.Close()
	imagesClient, err := compute.NewImagesRESTClient(ctx)
	if err != nil {
		return fmt.Errorf("NewImagesRESTClient: %w", err)
	}
	defer imagesClient.Close()

	// Get the source disk
	source_req := &computepb.GetDiskRequest{
		Disk:    sourceDiskName,
		Project: projectID,
		Zone:    zone,
	}

	disk, err := disksClient.Get(ctx, source_req)
	if err != nil {
		return fmt.Errorf("unable to get source disk: %w", err)
	}

	// Create the image
	req := computepb.InsertImageRequest{
		ForceCreate: &forceCreate,
		ImageResource: &computepb.Image{
			Name:             &imageName,
			SourceDisk:       disk.SelfLink,
			StorageLocations: storageLocations,
		},
		Project: projectID,
	}

	op, err := imagesClient.Insert(ctx, &req)

	if err = op.Wait(ctx); err != nil {
		return fmt.Errorf("unable to wait for the operation: %w", err)
	}

	fmt.Fprintf(w, "Disk image %s created\n", imageName)

	return nil
}

Java

Java

Before trying this sample, follow the Java setup instructions in the Compute Engine quickstart using client libraries. For more information, see the Compute Engine Java API reference documentation.

To authenticate to Compute Engine, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.


import com.google.cloud.compute.v1.Disk;
import com.google.cloud.compute.v1.DisksClient;
import com.google.cloud.compute.v1.Image;
import com.google.cloud.compute.v1.ImagesClient;
import com.google.cloud.compute.v1.InsertImageRequest;
import com.google.cloud.compute.v1.Instance;
import com.google.cloud.compute.v1.InstancesClient;
import com.google.cloud.compute.v1.Operation;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;

public class CreateImage {

  public static void main(String[] args)
      throws IOException, ExecutionException, InterruptedException, TimeoutException {
    // TODO(developer): Replace these variables before running the sample.

    // Project ID or project number of the Cloud project you use.
    String project = "your-project-id";
    // Zone of the disk you copy from.
    String zone = "europe-central2-b";
    // Name of the source disk you copy from.
    String sourceDiskName = "source-disk-name";
    // Name of the image you want to create.
    String imageName = "your-image-name";
    // Storage location for the image. If the value is undefined,
    // function will store the image in the multi-region closest to your image's source location.
    String storageLocation = "eu";
    // Create the image even if the source disk is attached to a running instance.
    boolean forceCreate = false;

    createImage(project, zone, sourceDiskName, imageName, storageLocation, forceCreate);
  }

  // Creates a new disk image from the specified source disk.
  public static void createImage(String project, String zone, String sourceDiskName,
      String imageName, String storageLocation, boolean forceCreate)
      throws IOException, ExecutionException, InterruptedException, TimeoutException {
    // Initialize client that will be used to send requests. This client only needs to be created
    // once, and can be reused for multiple requests. After completing all of your requests, call
    // the `client.close()` method on the client to safely
    // clean up any remaining background resources.
    try (ImagesClient imagesClient = ImagesClient.create();
        InstancesClient instancesClient = InstancesClient.create();
        DisksClient disksClient = DisksClient.create()) {

      Disk disk = disksClient.get(project, zone, sourceDiskName);

      // Getting instances where source disk is attached.
      for (String fullInstanceName : disk.getUsersList()) {
        Map<String, String> instanceInfo = parseInstanceName(fullInstanceName);