Move a VM instance between zones or regions

gcloud

In this example, you move a VM named myinstance that has two persistent disks named mybootdisk and mydatadisk, from europe-west1-c to us-west1-b.

1. Identify the disks that are associated with the VM that you want to move:

   gcloud compute instances describe myinstance --format="list(name,status,disks)"
   

   In this example, you find the following two associated disks for the myinstance VM:

   • A boot disk called mybootdisk
   • A data disk called mydatadisk

2. Set the auto-delete state of mybootdisk and mydatadisk to false to ensure that the disks are not automatically deleted when the VM is deleted.

   gcloud compute instances set-disk-auto-delete myinstance --zone europe-west1-c \
       --disk mybootdisk --no-auto-delete

   If the state was updated, gcloud compute returns the response Updated [...]. If the auto-delete state was already set to false, then gcloud compute returns:

   No change requested; skipping update for [myinstance].

3. (Optional) Save your VM metadata.

   When you delete your VM, the VM metadata is also removed. You can save that information in a separate file, then reapply the VM metadata to the new VM.

   Describe your VM's metadata like so:

   gcloud compute instances describe myinstance --zone europe-west1-c

   Save the contents to a separate file.

4. Create backups of your data by using persistent disk snapshots.

   As a precaution, create backups of your data while the persistent disks are still attached to the VM by using persistent disk snapshots. Before you take a snapshot, ensure that it is consistent with the state of the persistent disk by adhering to snapshot best practices.

   After you clear your disk buffers, create the snapshots:

   gcloud compute disks snapshot mybootdisk mydatadisk \
       --snapshot-names backup-mybootsnapshot,backup-mydatasnapshot \
       --zone europe-west1-c 

   To verify that the snapshot is created, run gcloud compute snapshots list.

5. (Optional) If you're moving a VM across zones within the same region, and you want to preserve its ephemeral internal or external IP address, promote the internal or external IP address to a static IP address, which you can reuse later.

6. Delete your VM.

   Deleting your VM shuts it down cleanly and detach any persistent disks.

   gcloud compute instances delete myinstance --zone europe-west1-c

   gcloud prompts you to confirm the deletion:

   
   The following VMs are deleted. Any attached disks configured to
   be auto-deleted are deleted unless they are attached to any other
   VMs or the `--keep-disks` flag is given and specifies them for keeping.
   Deleting a disk is irreversible and any data on the disk is lost.
   — [myinstance] in [europe-west1-c]
   Do you want to continue (Y/n)?

   Because you turned off the auto-delete state for the disks earlier in this process, enter Y to continue and ignore the warning.

7. Next, create another snapshot of both the boot disk and the data disk.

   gcloud compute disks snapshot mybootdisk mydatadisk \
       --snapshot-names mybootsnapshot,mydatasnapshot \
       --zone europe-west1-c 

   Created [.../mydatasnapshot].
   Created [.../mybootsnapshot].

8. (Optional) Delete your persistent disks.

   If you plan to reuse the names of the persistent disks for the new disks, you must delete the existing disks to release the names. Deleting your disks also saves on persistent disk storage costs.

   If you do not plan to reuse the same disk names, you don't need to delete them.

   gcloud compute disks delete mybootdisk mydatadisk --zone europe-west1-c

9. Create new persistent disks in us-west1-b from the snapshots you created. First create the boot disk.

   gcloud compute disks create mybootdiskb --source-snapshot mybootsnapshot \
       --zone us-west1-b

   Created [.../mybootdiskb].
   NAME        ZONE           SIZE_GB TYPE        STATUS
   mybootdiskb us-west1-b     100     pd-standard READY

   Then create the data disk.

   gcloud compute disks create mydatadiskb --source-snapshot mydatasnapshot \
       --zone us-west1-b

   Created [.../mydatadiskb].
   NAME        ZONE           SIZE_GB TYPE        STATUS
   mydatadiskb us-west1-b 4000    pd-standard READY

10. Recreate your VM in us-west1-b.

    • If you had opted to save your VM metadata in a file, for example myinstance.describe, you can use it to set the same metadata on your VM.

    • If your VM had a static external IP address, you can reassign that address to your new VM by specifying the --address [ADDRESS] option. If you are moving a VM across regions, you must pick a different external IP address for the new VM instance.

    • If your VM had a static internal IP address, you can reassign that address to your new VM by specifying the --private-network-ip ADDRESS option. If you are moving a VM across regions, you must pick a different internal IP address for the new VM instance.

    • If your VM included GPUs, add GPUs to the VM using the --accelerator option.

    • If the VM uses a specific subnet, add the --subnet [SUBNET_NAME] flag.

    For a complete list of additional flags, see gcloud compute instances create.

    gcloud compute instances create myinstanceb --machine-type n1-standard-4 \
        --zone us-west1-b \
        --disk name=mybootdiskb,boot=yes,mode=rw \
        --disk name=mydatadiskb,mode=rw 

    Created [.../myinstanceb].
    NAME        ZONE           MACHINE_TYPE  INTERNAL_IP    EXTERNAL_IP     STATUS
    myinstanceb us-west1-b     n1-standard-4 10.240.173.229 146.148.112.106 RUNNING

11. (Optional) Delete your persistent disk snapshots.

    After you confirm that your virtual machines are moved, save on storage costs by deleting the temporary snapshots that you created.

    gcloud compute snapshots delete mybootsnapshot mydatasnapshot

    If you no longer need your backup snapshots, delete those snapshots as well:

    gcloud compute snapshots delete backup-mybootsnapshot backup-mydatasnapshot

Go

1. Get the details of the VM and identify the disks that are attached to the VM.

   import (
   	"context"
   	"fmt"
   	"io"
   
   	compute "cloud.google.com/go/compute/apiv1"
   	computepb "cloud.google.com/go/compute/apiv1/computepb"
   )
   
   // getInstance prints a name of a VM instance in the given zone in the specified project.
   func getInstance(w io.Writer, projectID, zone, instanceName string) error {
   	// projectID := "your_project_id"
   	// zone := "europe-central2-b"
   	// instanceName := "your_instance_name"
   
   	ctx := context.Background()
   	instancesClient, err := compute.NewInstancesRESTClient(ctx)
   	if err != nil {
   		return fmt.Errorf("NewInstancesRESTClient: %w", err)
   	}
   	defer instancesClient.Close()
   
   	reqInstance := &computepb.GetInstanceRequest{
   		Project:  projectID,
   		Zone:     zone,
   		Instance: instanceName,
   	}
   
   	instance, err := instancesClient.Get(ctx, reqInstance)
   	if err != nil {
   		return fmt.Errorf("unable to get instance: %w", err)
   	}
   
   	fmt.Fprintf(w, "Instance: %s\n", instance.GetName())
   
   	return nil
   }
   

2. Set the auto-delete state of the boot disk and data disk to false to ensure that the disks are not automatically deleted when the VM is deleted.

   import (
   	"context"
   	"fmt"
   	"io"
   
   	compute "cloud.google.com/go/compute/apiv1"
   	computepb "cloud.google.com/go/compute/apiv1/computepb"
   )
   
   // 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
   }
   

3. Create backups of your data by using persistent disk snapshots.

   As a precaution, create backups of your data while the persistent disks are still attached to the VM by using persistent disk snapshots. Before you take a snapshot, ensure that it is consistent with the state of the persistent disk by adhering to snapshot best practices.

   After you clear your disk buffers, create the snapshots:

   import (
   	"context"
   	"fmt"
   	"io"
   
   	compute "cloud.google.com/go/compute/apiv1"
   	computepb "cloud.google.com/go/compute/apiv1/computepb"
   	"google.golang.org/protobuf/proto"
   )
   
   // createSnapshot creates a snapshot of a disk.
   func createSnapshot(
   	w io.Writer,
   	projectID, diskName, snapshotName, zone, region, location, diskProjectID string,
   ) error {
   	// projectID := "your_project_id"
   	// diskName := "your_disk_name"
   	// snapshotName := "your_snapshot_name"
   	// zone := "europe-central2-b"
   	// region := "eupore-central2"
   	// location = "eupore-central2"
   	// diskProjectID = "YOUR_DISK_PROJECT_ID"
   
   	ctx := context.Background()
   
   	snapshotsClient, err := compute.NewSnapshotsRESTClient(ctx)
   	if err != nil {
   		return fmt.Errorf("NewSnapshotsRESTClient: %w", err)
   	}
   	defer snapshotsClient.Close()
   
   	if zone == "" && region == "" {
   		return fmt.Errorf("you need to specify `zone` or `region` for this function to work")
   	}
   
   	if zone != "" && region != "" {
   		return fmt.Errorf("you can't set both `zone` and `region` parameters")
   	}
   
   	if diskProjectID == "" {
   		diskProjectID = projectID
   	}
   
   	disk := &computepb.Disk{}
   	locations := []string{}
   	if location != "" {
   		locations = append(locations, location)
   	}
   
   	if zone != "" {
   		disksClient, err := compute.NewDisksRESTClient(ctx)
   		if err != nil {
   			return fmt.Errorf("NewDisksRESTClient: %w", err)
   		}
   		defer disksClient.Close()
   
   		getDiskReq := &computepb.GetDiskRequest{
   			Project: projectID,
   			Zone:    zone,
   			Disk:    diskName,
   		}
   
   		disk, err = disksClient.Get(ctx, getDiskReq)
   		if err != nil {
   			return fmt.Errorf("unable to get disk: %w", err)
   		}
   	} else {
   		regionDisksClient, err := compute.NewRegionDisksRESTClient(ctx)
   		if err != nil {
   			return fmt.Errorf("NewRegionDisksRESTClient: %w", err)
   		}
   		defer regionDisksClient.Close()
   
   		getDiskReq := &computepb.GetRegionDiskRequest{
   			Project: projectID,
   			Region:  region,
   			Disk:    diskName,
   		}
   
   		disk, err = regionDisksClient.Get(ctx, getDiskReq)
   		if err != nil {
   			return fmt.Errorf("unable to get disk: %w", err)
   		}
   	}
   
   	req := &computepb.InsertSnapshotRequest{
   		Project: projectID,
   		SnapshotResource: &computepb.Snapshot{
   			Name:             proto.String(snapshotName),
   			SourceDisk:       proto.String(disk.GetSelfLink()),
   			StorageLocations: locations,
   		},
   	}
   
   	op, err := snapshotsClient.Insert(ctx, req)
   	if err != nil {
   		return fmt.Errorf("unable to create snapshot: %w", err)
   	}
   
   	if err = op.Wait(ctx); err != nil {
   		return fmt.Errorf("unable to wait for the operation: %w", err)
   	}
   
   	fmt.Fprintf(w, "Snapshot created\n")
   
   	return nil
   }
   

4. Delete your VM from the source zone.

   import (
   	"context"
   	"fmt"
   	"io"
   
   	compute "cloud.google.com/go/compute/apiv1"
   	computepb "cloud.google.com/go/compute/apiv1/computepb"
   )
   
   // deleteInstance sends a delete request to the Compute Engine API and waits for it to complete.
   func deleteInstance(w io.Writer, projectID, zone, instanceName string) error {
   	// projectID := "your_project_id"
   	// zone := "europe-central2-b"
   	// instanceName := "your_instance_name"
   	ctx := context.Background()
   	instancesClient, err := compute.NewInstancesRESTClient(ctx)
   	if err != nil {
   		return fmt.Errorf("NewInstancesRESTClient: %w", err)
   	}
   	defer instancesClient.Close()
   
   	req := &computepb.DeleteInstanceRequest{
   		Project:  projectID,
   		Zone:     zone,
   		Instance: instanceName,
   	}
   
   	op, err := instancesClient.Delete(ctx, req)
   	if err != nil {
   		return fmt.Errorf("unable to delete instance: %w", err)
   	}
   
   	if err = op.Wait(ctx); err != nil {
   		return fmt.Errorf("unable to wait for the operation: %w", err)
   	}
   
   	fmt.Fprintf(w, "Instance deleted\n")
   
   	return nil
   }
   

5. Next, create another snapshot of both the boot disk and the data disks.

   import (
   	"context"
   	"fmt"
   	"io"
   
   	compute "cloud.google.com/go/compute/apiv1"
   	computepb "cloud.google.com/go/compute/apiv1/computepb"
   	"google.golang.org/protobuf/proto"
   )
   
   // createSnapshot creates a snapshot of a disk.
   func createSnapshot(
   	w io.Writer,
   	projectID, diskName, snapshotName, zone, region, location, diskProjectID string,
   ) error {
   	// projectID := "your_project_id"
   	// diskName := "your_disk_name"
   	// snapshotName := "your_snapshot_name"
   	// zone := "europe-central2-b"
   	// region := "eupore-central2"
   	// location = "eupore-central2"
   	// diskProjectID = "YOUR_DISK_PROJECT_ID"
   
   	ctx := context.Background()
   
   	snapshotsClient, err := compute.NewSnapshotsRESTClient(ctx)
   	if err != nil {
   		return fmt.Errorf("NewSnapshotsRESTClient: %w", err)
   	}
   	defer snapshotsClient.Close()
   
   	if zone == "" && region == "" {
   		return fmt.Errorf("you need to specify `zone` or `region` for this function to work")
   	}
   
   	if zone != "" && region != "" {
   		return fmt.Errorf("you can't set both `zone` and `region` parameters")
   	}
   
   	if diskProjectID == "" {
   		diskProjectID = projectID
   	}
   
   	disk := &computepb.Disk{}
   	locations := []string{}
   	if location != "" {
   		locations = append(locations, location)
   	}
   
   	if zone != "" {
   		disksClient, err := compute.NewDisksRESTClient(ctx)
   		if err != nil {
   			return fmt.Errorf("NewDisksRESTClient: %w", err)
   		}
   		defer disksClient.Close()
   
   		getDiskReq := &computepb.GetDiskRequest{
   			Project: projectID,
   			Zone:    zone,
   			Disk:    diskName,
   		}
   
   		disk, err = disksClient.Get(ctx, getDiskReq)
   		if err != nil {
   			return fmt.Errorf("unable to get disk: %w", err)
   		}
   	} else {
   		regionDisksClient, err := compute.NewRegionDisksRESTClient(ctx)
   		if err != nil {
   			return fmt.Errorf("NewRegionDisksRESTClient: %w", err)
   		}
   		defer regionDisksClient.Close()
   
   		getDiskReq := &computepb.GetRegionDiskRequest{
   			Project: projectID,
   			Region:  region,
   			Disk:    diskName,
   		}
   
   		disk, err = regionDisksClient.Get(ctx, getDiskReq)
   		if err != nil {
   			return fmt.Errorf("unable to get disk: %w", err)
   		}
   	}
   
   	req := &computepb.InsertSnapshotRequest{
   		Project: projectID,
   		SnapshotResource: &computepb.Snapshot{
   			Name:             proto.String(snapshotName),
   			SourceDisk:       proto.String(disk.GetSelfLink()),
   			StorageLocations: locations,
   		},
   	}
   
   	op, err := snapshotsClient.Insert(ctx, req)
   	if err != nil {
   		return fmt.Errorf("unable to create snapshot: %w", err)
   	}
   
   	if err = op.Wait(ctx); err != nil {
   		return fmt.Errorf("unable to wait for the operation: %w", err)
   	}
   
   	fmt.Fprintf(w, "Snapshot created\n")
   
   	return nil
   }
   

6. (Optional) Delete your persistent disks.

   If you plan to reuse the names of the persistent disks for the new disks, you must delete the existing disks to release the names. Deleting your disks also saves on persistent disk storage costs.

   If you do not plan to reuse the same disk names, you don't need to delete them.

   import (
   	"context"
   	"fmt"
   	"io"
   
   	compute "cloud.google.com/go/compute/apiv1"
   	computepb "cloud.google.com/go/compute/apiv1/computepb"
   )
   
   // deleteDisk deletes a disk from a project.
   func deleteDisk(w io.Writer, projectID, zone, diskName string) error {
   	// projectID := "your_project_id"
   	// zone := "us-west3-b"
   	// diskName := "your_disk_name"
   
   	ctx := context.Background()
   	disksClient, err := compute.NewDisksRESTClient(ctx)
   	if err != nil {
   		return fmt.Errorf("NewDisksRESTClient: %w", err)
   	}
   	defer disksClient.Close()
   
   	req := &computepb.DeleteDiskRequest{
   		Project: projectID,
   		Zone:    zone,
   		Disk:    diskName,
   	}
   
   	op, err := disksClient.Delete(ctx, req)
   	if err != nil {
   		return fmt.Errorf("unable to delete disk: %w", err)
   	}
   
   	if err = op.Wait(ctx); err != nil {
   		return fmt.Errorf("unable to wait for the operation: %w", err)
   	}
   
   	fmt.Fprintf(w, "Disk deleted\n")
   
   	return nil
   }
   

7. Create new persistent disks in the destination zone from the snapshots you created. First create the boot disk, and then the data disks.

   import (
   	"context"
   	"fmt"
   	"io"
   
   	compute "cloud.google.com/go/compute/apiv1"
   	computepb "cloud.google.com/go/compute/apiv1/computepb"
   	"google.golang.org/protobuf/proto"
   )
   
   // createDiskFromSnapshot creates a new disk in a project in given zone.
   func createDiskFromSnapshot(
   	w io.Writer,
   	projectID, zone, diskName, diskType, snapshotLink string,
   	diskSizeGb int64,
   ) error {
   	// projectID := "your_project_id"
   	// zone := "us-west3-b" // should match diskType below
   	// diskName := "your_disk_name"
   	// diskType := "zones/us-west3-b/diskTypes/pd-ssd"
   	// snapshotLink := "projects/your_project_id/global/snapshots/snapshot_name"
   	// diskSizeGb := 120
   
   	ctx := context.Background()
   	disksClient, err := compute.NewDisksRESTClient(ctx)
   	if err != nil {
   		return fmt.Errorf("NewDisksRESTClient: %w", err)
   	}
   	defer disksClient.Close()
   
   	req := &computepb.InsertDiskRequest{
   		Project: projectID,
   		Zone:    zone,
   		DiskResource: &computepb.Disk{
   			Name:           proto.String(diskName),
   			Zone:           proto.String(zone),
   			Type:           proto.String(diskType),
   			SourceSnapshot: proto.String(snapshotLink),
   			SizeGb:         proto.Int64(diskSizeGb),
   		},
   	}
   
   	op, err := disksClient.Insert(ctx, req)
   	if err != nil {
   		return fmt.Errorf("unable to create disk: %w", err)
   	}
   
   	if err = op.Wait(ctx); err != nil {
   		return fmt.Errorf("unable to wait for the operation: %w", err)
   	}
   
   	fmt.Fprintf(w, "Disk created\n")
   
   	return nil
   }
   

8. Recreate your VM with the new disks in the destination zone.

   import (
   	"context"
   	"fmt"
   	"io"
   
   	compute "cloud.google.com/go/compute/apiv1"
   	computepb "cloud.google.com/go/compute/apiv1/computepb"
   	"google.golang.org/protobuf/proto"
   )
   
   // createWithExistingDisks create a new VM instance using selected disks.
   // The first disk in diskNames will be used as boot disk.
   func createWithExistingDisks(
   	w io.Writer,
   	projectID, zone, instanceName string,
   	diskNames []string,
   ) error {
   	// projectID := "your_project_id"
   	// zone := "europe-central2-b"
   	// instanceName := "your_instance_name"
   	// diskNames := []string{"boot_disk", "disk1", "disk2"}
   
   	ctx := context.Background()
   	instancesClient, err := compute.NewInstancesRESTClient(ctx)
   	if err != nil {
   		return fmt.Errorf("NewInstancesRESTClient: %w", err)
   	}
   	defer instancesClient.Close()
   
   	disksClient, err := compute.NewDisksRESTClient(ctx)
   	if err != nil {
   		return fmt.Errorf("NewDisksRESTClient: %w", err)
   	}
   	defer disksClient.Close()
   
   	disks := [](*computepb.Disk){}
   
   	for _, diskName := range diskNames {
   		reqDisk := &computepb.GetDiskRequest{
   			Project: projectID,
   			Zone:    zone,
   			Disk:    diskName,
   		}
   
   		disk, err := disksClient.Get(ctx, reqDisk)
   		if err != nil {
   			return fmt.Errorf("unable to get disk: %w", err)
   		}
   
   		disks = append(disks, disk)
   	}
   
   	attachedDisks := [](*computepb.AttachedDisk){}
   
   	for _, disk := range disks {
   		attachedDisk := &computepb.AttachedDisk{
   			Source: proto.String(disk.GetSelfLink()),
   		}
   		attachedDisks = append(attachedDisks, attachedDisk)
   	}
   
   	attachedDisks[0].Boot = proto.Bool(true)
   
   	instanceResource := &computepb.Instance{
   		Name:        proto.String(instanceName),
   		Disks:       attachedDisks,
   		MachineType: proto.String(fmt.Sprintf("zones/%s/machineTypes/n1-standard-1", zone)),
   		NetworkInterfaces: []*computepb.NetworkInterface{
   			{
   				Name: proto.String("global/networks/default"),
   			},
   		},
   	}
   
   	req := &computepb.InsertInstanceRequest{
   		Project:          projectID,
   		Zone:             zone,
   		InstanceResource: instanceResource,
   	}
   
   	op, err := instancesClient.Insert(ctx, req)
   	if err != nil {
   		return fmt.Errorf("unable to create instance: %w", err)
   	}
   
   	if err = op.Wait(ctx); err != nil {
   		return fmt.Errorf("unable to wait for the operation: %w", err)
   	}
   
   	fmt.Fprintf(w, "Instance created\n")
   
   	return nil
   }
   

9. (Optional) Delete the temporary disk snapshots. After you confirm that your virtual machines are moved, save on storage costs by deleting the temporary snapshots that you created.

   import (
   	"context"
   	"fmt"
   	"io"
   
   	compute "cloud.google.com/go/compute/apiv1"
   	computepb "cloud.google.com/go/compute/apiv1/computepb"
   )
   
   // deleteSnapshot deletes a snapshot of a disk.
   func deleteSnapshot(w io.Writer, projectID, snapshotName string) error {
   	// projectID := "your_project_id"
   	// snapshotName := "your_snapshot_name"
   
   	ctx := context.Background()
   	snapshotsClient, err := compute.NewSnapshotsRESTClient(ctx)
   	if err != nil {
   		return fmt.Errorf("NewSnapshotsRESTClient: %w", err)
   	}
   	defer snapshotsClient.Close()
   
   	req := &computepb.DeleteSnapshotRequest{
   		Project:  projectID,
   		Snapshot: snapshotName,
   	}
   
   	op, err := snapshotsClient.Delete(ctx, req)
   	if err != nil {
   		return fmt.Errorf("unable to delete snapshot: %w", err)
   	}
   
   	if err = op.Wait(ctx); err != nil {
   		return fmt.Errorf("unable to wait for the operation: %w", err)
   	}
   
   	fmt.Fprintf(w, "Snapshot deleted\n")
   
   	return nil
   }
   

Java

1. Get the details of the VM and identify the disks that are attached to the VM.

   
   import com.google.cloud.compute.v1.Instance;
   import com.google.cloud.compute.v1.InstancesClient;
   import java.io.IOException;
   
   public class GetInstance {
   
     public static void main(String[] args) throws IOException {
       // 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";
   
       // Name of the zone you want to use. For example: 'us-west3-b'.
       String zone = "europe-central2-b";
   
       // Name of the VM instance you want to query.
       String instanceName = "YOUR_INSTANCE_NAME";
   
       getInstance(projectId, zone, instanceName);
     }
   
     // Prints information about a VM instance in the given zone in the specified project.
     public static void getInstance(String projectId, String zone, String instanceName)
         throws IOException {
   
       // 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()) {
   
         Instance instance = instancesClient.get(projectId, zone, instanceName);
   
         System.out.printf("Retrieved the instance %s", instance.toString());
       }
     }
   }

2. Set the auto-delete state of the boot disk and data disk to false to ensure that the disks are not automatically deleted when the VM is deleted.

   
   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());
       }
     }
   }

3. Create backups of your data by using persistent disk snapshots.

   As a precaution, create backups of your data while the persistent disks are still attached to the VM by using persistent disk snapshots. Before you take a snapshot, ensure that it is consistent with the state of the persistent disk by adhering to snapshot best practices.

   After you clear your disk buffers, create the snapshots:

   
   import com.google.cloud.compute.v1.Disk;
   import com.google.cloud.compute.v1.DisksClient;
   import com.google.cloud.compute.v1.Operation;
   import com.google.cloud.compute.v1.RegionDisksClient;
   import com.google.cloud.compute.v1.Snapshot;
   import com.google.cloud.compute.v1.SnapshotsClient;
   import java.io.IOException;
   import java.util.concurrent.ExecutionException;
   import java.util.concurrent.TimeUnit;
   import java.util.concurrent.TimeoutException;
   
   public class CreateSnapshot {
   
     public static void main(String[] args)
         throws IOException, ExecutionException, InterruptedException, TimeoutException {
       // TODO(developer): Replace these variables before running the sample.
       // You need to pass `zone` or `region` parameter relevant to the disk you want to
       // snapshot, but not both. Pass `zone` parameter for zonal disks and `region` for
       // regional disks.
   
       // Project ID or project number of the Cloud project you want to use.
       String projectId = "YOUR_PROJECT_ID";
   
       // Name of the disk you want to create.
       String diskName = "YOUR_DISK_NAME";
   
       // Name of the snapshot that you want to create.
       String snapshotName = "YOUR_SNAPSHOT_NAME";
   
       // The zone of the source disk from which you create the snapshot (for zonal disks).
       String zone = "europe-central2-b";
   
       // The region of the source disk from which you create the snapshot (for regional disks).
       String region = "your-disk-region";
   
       // The Cloud Storage multi-region or the Cloud Storage region where you
       // want to store your snapshot.
       // You can specify only one storage location. Available locations:
       // https://cloud.google.com/storage/docs/locations#available-locations
       String location = "europe-central2";
   
       // Project ID or project number of the Cloud project that
       // hosts the disk you want to snapshot. If not provided, the value will be defaulted
       // to 'projectId' value.
       String diskProjectId = "YOUR_DISK_PROJECT_ID";
   
       createSnapshot(projectId, diskName, snapshotName, zone, region, location, diskProjectId);
     }
   
     // Creates a snapshot of a disk.
     public static void createSnapshot(String projectId, String diskName, String snapshotName,
         String zone, String region, String location, String diskProjectId)
         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 `snapshotsClient.close()` method on the client to safely
       // clean up any remaining background resources.
       try (SnapshotsClient snapshotsClient = SnapshotsClient.create()) {
   
         if (zone.isEmpty() && region.isEmpty()) {
           throw new Error("You need to specify 'zone' or 'region' for this function to work");
         }
   
         if (!zone.isEmpty() && !region.isEmpty()) {
           throw new Error("You can't set both 'zone' and 'region' parameters");
         }
   
         // If Disk's project id is not specified, then the projectId parameter will be used.
         if (diskProjectId.isEmpty()) {
           diskProjectId = projectId;
         }
   
         // If zone is not empty, use the DisksClient to create a disk.
         // Else, use the RegionDisksClient.
         Disk disk;
         if (!zone.isEmpty()) {
           DisksClient disksClient = DisksClient.create();
           disk = disksClient.get(projectId, zone, diskName);
         } else {
           RegionDisksClient regionDisksClient = RegionDisksClient.create();
           disk = regionDisksClient.get(diskProjectId, region, diskName);
         }
   
         // Set the snapshot properties.
         Snapshot snapshotResource;
         if (!location.isEmpty()) {
           snapshotResource = Snapshot.newBuilder()
               .setName(snapshotName)
               .setSourceDisk(disk.getSelfLink())
               .addStorageLocations(location)
               .build();
         } else {
           snapshotResource = Snapshot.newBuilder()
               .setName(snapshotName)
               .setSourceDisk(disk.getSelfLink())
               .build();
         }
   
         // Wait for the operation to complete.
         Operation operation = snapshotsClient.insertAsync(projectId, snapshotResource)
             .get(3, TimeUnit.MINUTES);
   
         if (operation.hasError()) {
           System.out.println("Snapshot creation failed!" + operation);
           return;
         }
   
         // Retrieve the created snapshot.
         Snapshot snapshot = snapshotsClient.get(projectId, snapshotName);
         System.out.printf("Snapshot created: %s", snapshot.getName());
   
       }
     }
   }

4. Delete your VM from the source zone.

   
   import com.google.api.gax.longrunning.OperationFuture;
   import com.google.cloud.compute.v1.DeleteInstanceRequest;
   import com.google.cloud.compute.v1.InstancesClient;
   import com.google.cloud.compute.v1.Operation;
   import java.io.IOException;
   import java.util.concurrent.ExecutionException;
   import java.util.concurrent.TimeUnit;
   import java.util.concurrent.TimeoutException;
   
   public class DeleteInstance {
   
     public static void main(String[] args)
         throws IOException, InterruptedException, ExecutionException, TimeoutException {
       // TODO(developer): Replace these variables before running the sample.
       String project = "your-project-id";
       String zone = "zone-name";
       String instanceName = "instance-name";
       deleteInstance(project, zone, instanceName);
     }
   
     // Delete the instance specified by `instanceName`
     // if it's present in the given project and zone.
     public static void deleteInstance(String project, String zone, String instanceName)
         throws IOException, InterruptedException, ExecutionException, 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()) {
   
         System.out.printf("Deleting instance: %s ", instanceName);
   
         // Describe which instance is to be deleted.
         DeleteInstanceRequest deleteInstanceRequest = DeleteInstanceRequest.newBuilder()
             .setProject(project)
             .setZone(zone)
             .setInstance(instanceName).build();
   
         OperationFuture<Operation, Operation> operation = instancesClient.deleteAsync(
             deleteInstanceRequest);
         // Wait for the operation to complete.
         Operation response = operation.get(3, TimeUnit.MINUTES);
   
         if (response.hasError()) {
           System.out.println("Instance deletion failed ! ! " + response);
           return;
         }
         System.out.println("Operation Status: " + response.getStatus());
       }
     }
   }

5. Next, create another snapshot of both the boot disk and the data disks.

   
   import com.google.cloud.compute.v1.Disk;
   import com.google.cloud.compute.v1.DisksClient;
   import com.google.cloud.compute.v1.Operation;
   import com.google.cloud.compute.v1.RegionDisksClient;
   import com.google.cloud.compute.v1.Snapshot;
   import com.google.cloud.compute.v1.SnapshotsClient;
   import java.io.IOException;
   import java.util.concurrent.ExecutionException;
   import java.util.concurrent.TimeUnit;
   import java.util.concurrent.TimeoutException;
   
   public class CreateSnapshot {
   
     public static void main(String[] args)
         throws IOException, ExecutionException, InterruptedException, TimeoutException {
       // TODO(developer): Replace these variables before running the sample.
       // You need to pass `zone` or `region` parameter relevant to the disk you want to
       // snapshot, but not both. Pass `zone` parameter for zonal disks and `region` for
       // regional disks.
   
       // Project ID or project number of the Cloud project you want to use.
       String projectId = "YOUR_PROJECT_ID";
   
       // Name of the disk you want to create.
       String diskName = "YOUR_DISK_NAME";
   
       // Name of the snapshot that you want to create.
       String snapshotName = "YOUR_SNAPSHOT_NAME";
   
       // The zone of the source disk from which you create the snapshot (for zonal disks).
       String zone = "europe-central2-b";
   
       // The region of the source disk from which you create the snapshot (for regional disks).
       String region = "your-disk-region";
   
       // The Cloud Storage multi-region or the Cloud Storage region where you
       // want to store your snapshot.
       // You can specify only one storage location. Available locations:
       // https://cloud.google.com/storage/docs/locations#available-locations
       String location = "europe-central2";
   
       // Project ID or project number of the Cloud project that
       // hosts the disk you want to snapshot. If not provided, the value will be defaulted
       // to 'projectId' value.
       String diskProjectId = "YOUR_DISK_PROJECT_ID";
   
       createSnapshot(projectId, diskName, snapshotName, zone, region, location, diskProjectId);
     }
   
     // Creates a snapshot of a disk.
     public static void createSnapshot(String projectId, String diskName, String snapshotName,
         String zone, String region, String location, String diskProjectId)
         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 `snapshotsClient.close()` method on the client to safely
       // clean up any remaining background resources.
       try (SnapshotsClient snapshotsClient = SnapshotsClient.create()) {
   
         if (zone.isEmpty() && region.isEmpty()) {
           throw new Error("You need to specify 'zone' or 'region' for this function to work");
         }
   
         if (!zone.isEmpty() && !region.isEmpty()) {
           throw new Error("You can't set both 'zone' and 'region' parameters");
         }
   
         // If Disk's project id is not specified, then the projectId parameter will be used.
         if (diskProjectId.isEmpty()) {
           diskProjectId = projectId;
         }
   
         // If zone is not empty, use the DisksClient to create a disk.
         // Else, use the RegionDisksClient.
         Disk disk;
         if (!zone.isEmpty()) {
           DisksClient disksClient = DisksClient.create();
           disk = disksClient.get(projectId, zone, diskName);
         } else {
           RegionDisksClient regionDisksClient = RegionDisksClient.create();
           disk = regionDisksClient.get(diskProjectId, region, diskName);
         }
   
         // Set the snapshot properties.
         Snapshot snapshotResource;
         if (!location.isEmpty()) {
           snapshotResource = Snapshot.newBuilder()
               .setName(snapshotName)
               .setSourceDisk(disk.getSelfLink())
               .addStorageLocations(location)
               .build();
         } else {
           snapshotResource = Snapshot.newBuilder()
               .setName(snapshotName)
               .setSourceDisk(disk.getSelfLink())
               .build();
         }
   
         // Wait for the operation to complete.
         Operation operation = snapshotsClient.insertAsync(projectId, snapshotResource)
             .get(3, TimeUnit.MINUTES);
   
         if (operation.hasError()) {
           System.out.println("Snapshot creation failed!" + operation);
           return;
         }
   
         // Retrieve the created snapshot.
         Snapshot snapshot = snapshotsClient.get(projectId, snapshotName);
         System.out.printf("Snapshot created: %s", snapshot.getName());
   
       }
     }
   }

6. (Optional) Delete your persistent disks.

   If you plan to reuse the names of the persistent disks for the new disks, you must delete the existing disks to release the names. Deleting your disks also saves on persistent disk storage costs.

   If you do not plan to reuse the same disk names, you don't need to delete them.

   
   import com.google.cloud.compute.v1.DeleteDiskRequest;
   import com.google.cloud.compute.v1.DisksClient;
   import com.google.cloud.compute.v1.Operation;
   import java.io.IOException;
   import java.util.concurrent.ExecutionException;
   import java.util.concurrent.TimeUnit;
   import java.util.concurrent.TimeoutException;
   
   public class DeleteDisk {
   
     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 from where you want to delete the disk.
       String zone = "europe-central2-b";
   
       // Name of the disk you want to delete.
       String diskName = "YOUR_DISK_NAME";
   
       deleteDisk(projectId, zone, diskName);
     }
   
     // Deletes a disk from a project.
     public static void deleteDisk(String projectId, String zone, String diskName)
         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 `disksClient.close()` method on the client to safely
       // clean up any remaining background resources.
       try (DisksClient disksClient = DisksClient.create()) {
   
         // Create the request object.
         DeleteDiskRequest deleteDiskRequest = DeleteDiskRequest.newBuilder()
             .setProject(projectId)
             .setZone(zone)
             .setDisk(diskName)
             .build();
   
         // Wait for the delete disk operation to complete.
         Operation response = disksClient.deleteAsync(deleteDiskRequest)
             .get(3, TimeUnit.MINUTES);
   
         if (response.hasError()) {
           System.out.println("Disk deletion failed!" + response);
           return;
         }
         System.out.println("Operation Status: " + response.getStatus());
       }
     }
   }

7. Create new persistent disks in the destination zone from the snapshots you created. First create the boot disk, and then the data disks.

   
   import com.google.cloud.compute.v1.Disk;
   import com.google.cloud.compute.v1.DisksClient;
   import com.google.cloud.compute.v1.InsertDiskRequest;
   import com.google.cloud.compute.v1.Operation;
   import java.io.IOException;
   import java.util.concurrent.ExecutionException;
   import java.util.concurrent.TimeUnit;
   import java.util.concurrent.TimeoutException;
   
   public class CreateDiskFromSnapshot {
   
     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";
   
       // Name of the zone in which you want to create the disk.
       String zone = "europe-central2-b";
   
       // Name of the disk you want to create.
       String diskName = "YOUR_DISK_NAME";
   
       // The type of disk you want to create. This value uses the following format:
       // "zones/{zone}/diskTypes/(pd-standard|pd-ssd|pd-balanced|pd-extreme)".
       // For example: "zones/us-west3-b/diskTypes/pd-ssd"
       String diskType = String.format("zones/%s/diskTypes/pd-ssd", zone);
   
       // Size of the new disk in gigabytes.
       long diskSizeGb = 10;
   
       // The full path and name of the snapshot that you want to use as the source for the new disk.
       // This value uses the following format:
       // "projects/{projectName}/global/snapshots/{snapshotName}"
       String snapshotLink = String.format("projects/%s/global/snapshots/%s", projectId,
           "SNAPSHOT_NAME");
   
       createDiskFromSnapshot(projectId, zone, diskName, diskType, diskSizeGb, snapshotLink);
     }
   
     // Creates a new disk in a project in given zone, using a snapshot.
     public static void createDiskFromSnapshot(String projectId, String zone, String diskName,
         String diskType, long diskSizeGb, String snapshotLink)
         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 `disksClient.close()` method on the client to safely
       // clean up any remaining background resources.
       try (DisksClient disksClient = DisksClient.create()) {
   
         // Set the disk properties and the source snapshot.
         Disk disk = Disk.newBuilder()
             .setName(diskName)
             .setZone(zone)
             .setSizeGb(diskSizeGb)
             .setType(diskType)
             .setSourceSnapshot(snapshotLink)
             .build();
   
         // Create the insert disk request.
         InsertDiskRequest insertDiskRequest = InsertDiskRequest.newBuilder()
             .setProject(projectId)
             .setZone(zone)
             .setDiskResource(disk)
             .build();
   
         // Wait for the create disk operation to complete.
         Operation response = disksClient.insertAsync(insertDiskRequest)
             .get(3, TimeUnit.MINUTES);
   
         if (response.hasError()) {
           System.out.println("Disk creation failed!" + response);
           return;
         }
         System.out.println("Disk created. Operation Status: " + response.getStatus());
       }
     }
   }

8. Recreate your VM with the new disks in the destination zone.

   
   import com.google.cloud.compute.v1.AttachedDisk;
   import com.google.cloud.compute.v1.Disk;
   import com.google.cloud.compute.v1.DisksClient;
   import com.google.cloud.compute.v1.InsertInstanceRequest;
   import com.google.cloud.compute.v1.Instance;
   import com.google.cloud.compute.v1.InstancesClient;
   import com.google.cloud.compute.v1.NetworkInterface;
   import com.google.cloud.compute.v1.Operation;
   import java.io.IOException;
   import java.util.ArrayList;
   import java.util.List;
   import java.util.concurrent.ExecutionException;
   import java.util.concurrent.TimeUnit;
   import java.util.concurrent.TimeoutException;
   
   public class CreateInstanceWithExistingDisks {
   
     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";
   
       // Name of the zone to create the instance in. For example: "us-west3-b"
       String zone = "europe-central2-b";
   
       // Name of the new virtual machine (VM) instance.
       String instanceName = "YOUR_INSTANCE_NAME";
   
       // Array of disk names to be attached to the new virtual machine.
       // First disk in this list will be used as the boot disk.
       List<String> diskNames = List.of("your-boot-disk", "another-disk1", "another-disk2");
   
       createInstanceWithExistingDisks(projectId, zone, instanceName, diskNames);
     }
   
     // Create a new VM instance using the selected disks.
     // The first disk in diskNames will be used as the boot disk.
     public static void createInstanceWithExistingDisks(String projectId, String zone,
         String instanceName, List<String> diskNames)
         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();
           DisksClient disksClient = DisksClient.create()) {
   
         if (diskNames.size() == 0) {
           throw new Error("At least one disk should be provided");
         }
   
         // Create the list of attached disks to be used in instance creation.
         List<AttachedDisk> attachedDisks = new ArrayList<>();
         for (int i = 0; i < diskNames.size(); i++) {
           String diskName = diskNames.get(i);
           Disk disk = disksClient.get(projectId, zone, diskName);
           AttachedDisk attDisk = null;
   
           if (i == 0) {
             // Make the first disk in the list as the boot disk.
             attDisk = AttachedDisk.newBuilder()
                 .setSource(disk.getSelfLink())
                 .setBoot(true)
                 .build();
           } else {
             attDisk = AttachedDisk.newBuilder()
                 .setSource(disk.getSelfLink())
                 .build();
           }
           attachedDisks.add(attDisk);
         }
   
         // Create the instance.
         Instance instance = Instance.newBuilder()
             .setName(instanceName)
             // Add the attached disks to the instance.
             .addAllDisks(attachedDisks)
             .setMachineType(String.format("zones/%s/machineTypes/n1-standard-1", zone))
             .addNetworkInterfaces(
                 NetworkInterface.newBuilder().setName("global/networks/default").build())
             .build();
   
         // Create the insert instance request.
         InsertInstanceRequest insertInstanceRequest = InsertInstanceRequest.newBuilder()
             .setProject(projectId)
             .setZone(zone)
             .setInstanceResource(instance)
             .build();
   
         // Wait for the create operation to complete.
         Operation response = instancesClient.insertAsync(insertInstanceRequest)
             .get(3, TimeUnit.MINUTES);
   
         if (response.hasError()) {
           System.out.println("Instance creation failed!" + response);
           return;
         }
         System.out.println("Operation Status: " + response.getStatus());
   
       }
     }
   }

9. (Optional) Delete the temporary disk snapshots. After you confirm that your virtual machines are moved, save on storage costs by deleting the temporary snapshots that you created.

   
   import com.google.cloud.compute.v1.Operation;
   import com.google.cloud.compute.v1.SnapshotsClient;
   import java.io.IOException;
   import java.util.concurrent.ExecutionException;
   import java.util.concurrent.TimeUnit;
   import java.util.concurrent.TimeoutException;
   
   public class DeleteSnapshot {
   
     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";
   
       // Name of the snapshot to be deleted.
       String snapshotName = "YOUR_SNAPSHOT_NAME";
   
       deleteSnapshot(projectId, snapshotName);
     }
   
     // Delete a snapshot of a disk.
     public static void deleteSnapshot(String projectId, String snapshotName)
         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 `snapshotsClient.close()` method on the client to safely
       // clean up any remaining background resources.
       try (SnapshotsClient snapshotsClient = SnapshotsClient.create()) {
   
         Operation operation = snapshotsClient.deleteAsync(projectId, snapshotName)
             .get(3, TimeUnit.MINUTES);
   
         if (operation.hasError()) {
           System.out.println("Snapshot deletion failed!" + operation);
           return;
         }
   
         System.out.println("Snapshot deleted!");
       }
     }
   }

Node.js

1. Get the details of the VM and identify the disks that are attached to the VM.

   /**
    * 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 compute = require('@google-cloud/compute');
   
   async function getInstance() {
     const instancesClient = new compute.InstancesClient();
   
     const [instance] = await instancesClient.get({
       project: projectId,
       zone,
       instance: instanceName,
     });
   
     console.log(
       `Instance ${instanceName} data:\n${JSON.stringify(instance, null, 4)}`
     );
   }
   getInstance();

2. Set the auto-delete state of the boot disk and data disk to false to ensure that the disks are not automatically deleted when the VM is deleted.

   /**
    * 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();

3. Create backups of your data by using persistent disk snapshots.

   As a precaution, create backups of your data while the persistent disks are still attached to the VM by using persistent disk snapshots. Before you take a snapshot, ensure that it is consistent with the state of the persistent disk by adhering to snapshot best practices.

   After you clear your disk buffers, create the snapshots:

   /**
    * TODO(developer): Uncomment and replace these variables before running the sample.
    */
   // const projectId = 'YOUR_PROJECT_ID';
   // const diskName = 'YOUR_DISK_NAME';
   // const snapshotName = 'YOUR_SNAPSHOT_NAME';
   // const zone = 'europe-central2-b';
   // const region = '';
   // const location = 'europe-central2';
   // let diskProjectId = 'YOUR_DISK_PROJECT_ID';
   
   const compute = require('@google-cloud/compute');
   
   async function createSnapshot() {
     const snapshotsClient = new compute.SnapshotsClient();
   
     let disk;
   
     if (!zone && !region) {
       throw new Error(
         'You need to specify `zone` or `region` for this function to work.'
       );
     }
   
     if (zone && region) {
       throw new Error("You can't set both `zone` and `region` parameters");
     }
   
     if (!diskProjectId) {
       diskProjectId = projectId;
     }
   
     if (zone) {
       const disksClient = new compute.DisksClient();
       [disk] = await disksClient.get({
         project: diskProjectId,
         zone,
         disk: diskName,
       });
     } else {
       const regionDisksClient = new compute.RegionDisksClient();
       [disk] = await regionDisksClient.get({
         project: diskProjectId,
         region,
         disk: diskName,
       });
     }
   
     const snapshotResource = {
       name: snapshotName,
       sourceDisk: disk.selfLink,
     };
   
     if (location) {
       snapshotResource.storageLocations = [location];
     }
   
     const [response] = await snapshotsClient.insert({
       project: projectId,
       snapshotResource,
     });
     let operation = response.latestResponse;
     const operationsClient = new compute.GlobalOperationsClient();
   
     // Wait for the create snapshot operation to complete.
     while (operation.status !== 'DONE') {
       [operation] = await operationsClient.wait({
         operation: operation.name,
         project: projectId,
       });
     }
   
     console.log('Snapshot created.');
   }
   
   createSnapshot();

4. Delete your VM from the source zone.

   /**
    * TODO(developer): Uncomment these variables before running the sample.
    */
   // const projectId = 'YOUR_PROJECT_ID';
   // const zone = 'europe-central2-b'
   // const instanceName = 'YOUR_INSTANCE_NAME';
   
   const compute = require('@google-cloud/compute');
   
   // Delete the instance specified by `instanceName` if it's present in the given project and zone.
   async function deleteInstance() {
     const instancesClient = new compute.InstancesClient();
   
     console.log(`Deleting ${instanceName} from ${zone}...`);
   
     const [response] = await instancesClient.delete({
       project: projectId,
       zone,
       instance: instanceName,
     });
     let operation = response.latestResponse;
     const operationsClient = new compute.ZoneOperationsClient();
   
     // Wait for the delete operation to complete.
     while (operation.status !== 'DONE') {
       [operation] = await operationsClient.wait({
         operation: operation.name,
         project: projectId,
         zone: operation.zone.split('/').pop(),
       });
     }
   
     console.log('Instance deleted.');
   }
   
   deleteInstance();

5. Next, create another snapshot of both the boot disk and the data disks.

   /**
    * TODO(developer): Uncomment and replace these variables before running the sample.
    */
   // const projectId = 'YOUR_PROJECT_ID';
   // const diskName = 'YOUR_DISK_NAME';
   // const snapshotName = 'YOUR_SNAPSHOT_NAME';
   // const zone = 'europe-central2-b';
   // const region = '';
   // const location = 'europe-central2';
   // let diskProjectId = 'YOUR_DISK_PROJECT_ID';
   
   const compute = require('@google-cloud/compute');
   
   async function createSnapshot() {
     const snapshotsClient = new compute.SnapshotsClient();
   
     let disk;
   
     if (!zone && !region) {
       throw new Error(
         'You need to specify `zone` or `region` for this function to work.'
       );
     }
   
     if (zone && region) {
       throw new Error("You can't set both `zone` and `region` parameters");
     }
   
     if (!diskProjectId) {
       diskProjectId = projectId;
     }
   
     if (zone) {
       const disksClient = new compute.DisksClient();
       [disk] = await disksClient.get({
         project: diskProjectId,
         zone,
         disk: diskName,
       });
     } else {
       const regionDisksClient = new compute.RegionDisksClient();
       [disk] = await regionDisksClient.get({
         project: diskProjectId,
         region,
         disk: diskName,
       });
     }
   
     const snapshotResource = {
       name: snapshotName,
       sourceDisk: disk.selfLink,
     };
   
     if (location) {
       snapshotResource.storageLocations = [location];
     }
   
     const [response] = await snapshotsClient.insert({
       project: projectId,
       snapshotResource,
     });
     let operation = response.latestResponse;
     const operationsClient = new compute.GlobalOperationsClient();
   
     // Wait for the create snapshot operation to complete.
     while (operation.status !== 'DONE') {
       [operation] = await operationsClient.wait({
         operation: operation.name,
         project: projectId,
       });
     }
   
     console.log('Snapshot created.');
   }
   
   createSnapshot();

6. (Optional) Delete your persistent disks.

   If you plan to reuse the names of the persistent disks for the new disks, you must delete the existing disks to release the names. Deleting your disks also saves on persistent disk storage costs.

   If you do not plan to reuse the same disk names, you don't need to delete them.

   /**
    * TODO(developer): Uncomment and replace these variables before running the sample.
    */
   // const projectId = 'YOUR_PROJECT_ID';
   // const zone = 'europe-central2-b';
   // const diskName = 'YOUR_DISK_NAME';
   
   const compute = require('@google-cloud/compute');
   
   async function deleteDisk() {
     const disksClient = new compute.DisksClient();
   
     const [response] = await disksClient.delete({
       project: projectId,
       zone,
       disk: diskName,
     });
     let operation = response.latestResponse;
     const operationsClient = new compute.ZoneOperationsClient();
   
     // Wait for the create disk operation to complete.
     while (operation.status !== 'DONE') {
       [operation] = await operationsClient.wait({
         operation: operation.name,
         project: projectId,
         zone: operation.zone.split('/').pop(),
       });
     }
   
     console.log('Disk deleted.');
   }
   
   deleteDisk();

7. Create new persistent disks in the destination zone from the snapshots you created. First create the boot disk, and then the data disks.

   /**
    * TODO(developer): Uncomment and replace these variables before running the sample.
    */
   // const projectId = 'YOUR_PROJECT_ID';
   // const zone = 'europe-central2-b';
   // const diskName = 'YOUR_DISK_NAME';
   // const diskType = 'zones/us-west3-b/diskTypes/pd-ssd';
   // const diskSizeGb = 10;
   // const snapshotLink = 'projects/project_name/global/snapshots/snapshot_name';
   
   const compute = require('@google-cloud/compute');
   
   async function createDiskFromSnapshot() {
     const disksClient = new compute.DisksClient();
   
     const [response] = await disksClient.insert({
       project: projectId,
       zone,
       diskResource: {
         sizeGb: diskSizeGb,
         name: diskName,
         zone,
         type: diskType,
         sourceSnapshot: snapshotLink,
       },
     });
     let operation = response.latestResponse;
     const operationsClient = new compute.ZoneOperationsClient();
   
     // Wait for the create disk operation to complete.
     while (operation.status !== 'DONE') {
       [operation] = await operationsClient.wait({
         operation: operation.name,
         project: projectId,
         zone: operation.zone.split('/').pop(),
       });
     }
   
     console.log('Disk created.');
   }
   
   createDiskFromSnapshot();

8. Recreate your VM with the new disks in the destination zone.

   /**
    * 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 diskNames = ['boot_disk', 'disk1', 'disk2'];
   
   const compute = require('@google-cloud/compute');
   
   async function createWithExistingDisks() {
     const instancesClient = new compute.InstancesClient();
     const disksClient = new compute.DisksClient();
   
     if (diskNames.length < 1) {
       throw new Error('At least one disk should be provided');
     }
   
     const disks = [];
     for (const diskName of diskNames) {
       const [disk] = await disksClient.get({
         project: projectId,
         zone,
         disk: diskName,
       });
       disks.push(disk);
     }
   
     const attachedDisks = [];
   
     for (const disk of disks) {
       attachedDisks.push({
         source: disk.selfLink,
       });
     }
   
     attachedDisks[0].boot = true;
   
     const [response] = await instancesClient.insert({
       project: projectId,
       zone,
       instanceResource: {
         name: instanceName,
         disks: attachedDisks,
         machineType: `zones/${zone}/machineTypes/n1-standard-1`,
         networkInterfaces: [
           {
             name: 'global/networks/default',
           },
         ],
       },
     });
     let operation = response.latestResponse;
     const operationsClient = new compute.ZoneOperationsClient();
   
     // Wait for the create operation to complete.
     while (operation.status !== 'DONE') {
       [operation] = await operationsClient.wait({
         operation: operation.name,
         project: projectId,
         zone: operation.zone.split('/').pop(),
       });
     }
   
     console.log('Instance created.');
   }
   
   createWithExistingDisks();

9. (Optional) Delete the temporary disk snapshots. After you confirm that your virtual machines are moved, save on storage costs by deleting the temporary snapshots that you created.

   /**
    * TODO(developer): Uncomment and replace these variables before running the sample.
    */
   // const projectId = 'YOUR_PROJECT_ID';
   // const snapshotName = 'YOUR_SNAPSHOT_NAME';
   
   const compute = require('@google-cloud/compute');
   
   async function deleteSnapshot() {
     const snapshotsClient = new compute.SnapshotsClient();
   
     const [response] = await snapshotsClient.delete({
       project: projectId,
       snapshot: snapshotName,
     });
     let operation = response.latestResponse;
     const operationsClient = new compute.GlobalOperationsClient();
   
     // Wait for the create disk operation to complete.
     while (operation.status !== 'DONE') {
       [operation] = await operationsClient.wait({
         operation: operation.name,
         project: projectId,
       });
     }
   
     console.log('Snapshot deleted.');
   }
   
   deleteSnapshot();