Making a VM preemptible

Written by

Yandex Cloud

Improved by

Ivan F.

Updated at October 30, 2024

Creating a preemptible VM
Changing a VM's type

You can create a preemptible VM or change the type of an existing one.

Creating a preemptible VM

To create a preemptible VM:

Management console

CLI

Terraform

API

In the management console, select the folder where you want to create your preemptible VM.
In the list of services, select Compute Cloud.
In the left-hand panel, select Virtual machines.
Click Create virtual machine.
Under Boot disk image, select an image and OS version.

To create a VM instance from an existing boot disk, go to the Custom tab and select the boot disk you need. To update its settings, click next to the disk name.
Under Location, select an availability zone to host your preemptible VM.
(Optional) Configure the boot disk under Disks and file storages:
- Select the disk type.
- Specify the required disk size.
- (Optional) To encrypt a boot disk or a secondary disk, under Disks and file storages, click to the right of the disk name and set encryption parameters for the disk:
  - Select Encrypted disk.
  - In the KMS key field, select the key to encrypt the disk with. To create a new key, click Create new key.
  - In the Service account field, select a service account with the kms.keys.encrypterDecrypter role for the specified key. To create a service account, click Create new account.
  The encryption feature in Compute Cloud is currently at the Preview stage. To access it, open the resource creation page and click Request access under Encryption or contact support.
  
  If you deactivate the key used to encrypt a disk or snapshot, access to the data will be suspended until you reactivate the key.
  
  Alert
  
  If you destroy the key or its version used to encrypt a disk or snapshot, access to the data will be irrevocably lost. Learn more in Destroying key versions.
If you are creating a VM instance from an existing boot disk, update the settings of that disk in the Custom tab under Boot disk image at the top of the form.
(Optional) Add a secondary disk:
- Under Disks and file storages, click Add
- In the window that opens, select Disk. You can select an existing disk or create a new one, either empty or from a snapshot / image.
  
  For example, to create a new empty disk:
  - Select Create new.
  - In the Contents field, select Empty.
  - Specify the disk name.
  - Select the disk type.
  - Specify the required disk size and block size.
  - (Optional) Enable the Additional option in the Delete along with the virtual machine field if you need to automatically delete this disk when deleting the VM.
  - Click Add disk.
(Optional) Connect a file storage:
- Under Disks and file storages, click Add.
  - In the window that opens, select File storage and select the storage you want to connect from the list.
    
    If you do not have any file storages, click Create file storage to create a new one.
  - Click Add file storage.
Under Computing resources:
- Go to the Custom tab.
- Choose a platform.
- Specify the guaranteed share and required number of vCPUs, as well as RAM size.
- In the Additional field, enable the Preemptible option.
- (Optional) Enable a software-accelerated network.
Under Network settings:
- In the Subnet field, enter the ID of a subnet in the new VM’s availability zone. Alternatively, you can select a cloud network from the list.
  - Each network must have at least one subnet. If there is no subnet, create one by selecting Create subnet.
  - If you do not have a network, click Create network to create one:
    - In the window that opens, enter the network name and select the folder to host the network.
    - (Optional) Select the Create subnets option to automatically create subnets in all availability zones.
    - Click Create network.
- In the Public IP field, choose a method for assigning an IP address:
  - Auto: Assign a random IP address from the Yandex Cloud IP address pool. In this case, you can enable DDoS protection using the option below.
  - List: Select a public IP address from the list of previously reserved static addresses. For more information, see Converting a dynamic public IP address to static.
  - No address: Do not assign a public IP address.
- Select the appropriate security groups. If you leave this field empty, the default security group will be assigned to the VM.
- Expand the Additional section and select a method for internal IP address assignment in the Internal IPv4 address field:
  - Auto: Assign a random IP address from the pool of IP addresses available in the selected subnet.
  - List: Select a private IP address from the list of previously reserved IP addresses. Click Reserve to reserve a private IP address in the selected subnet if needed.
  - Enable the DDoS protection option, if needed. The option is available if you previously selected the automatic IP assignment method in the public address settings.
- (Optional) Create records for the VM in the DNS zone:
  - Expand the DNS settings for internal addresses section and click Add record.
  - Specify the zone, FQDN, and TTL for the record. When setting the FQDN, you can select Detect automatically for the zone.
    You can add multiple records to internal DNS zones. For more information, see Cloud DNS integration with Compute Cloud.
  - To create another record, click Add record.
If you want to attach an additional network interface to your VM, click Add network interface and repeat the settings from this step for the new interface. You can add up to eight network interfaces to a single VM.
Under Access, specify the data for access to the VM:
- (Optional) Enable VM access via OS Login. The option is available for Linux images from Cloud Marketplace with OS Login in their names.
- Enter the username into the Login field.
  
  Alert
  
  Do not use root or other usernames reserved by the OS. To perform operations requiring superuser permissions, use the sudo command.
- In the SSH key field, paste the contents of the public key file. You need to create a key pair for the SSH connection yourself. To learn how, see Connecting to a VM via SSH.
If you want to add several users with SSH keys to the VM at the same time, specify these users' data under Metadata. You can also use metadata to install additional software on a VM when creating it.

In public Linux images provided by Yandex Cloud, the functionality of connecting over SSH using login and password is disabled by default.
Under General information, specify the preemptible VM name:
- The name must be from 3 to 63 characters long.
- It may contain lowercase Latin letters, numbers, and hyphens.
- The first character must be a letter and the last character cannot be a hyphen.
Note

The VM name is used to generate an internal FQDN only once: when creating a VM. If the internal FQDN is important to you, choose an appropriate name for the VM at the creation stage.
Under Additional:
- (Optional) Select or create a service account. With a service account, you can flexibly configure access rights for your resources.
- (Optional) Grant access to the serial console.
- (Optional) Under Backup, enable Connect and select or create a backup policy to back up your VMs automatically using Cloud Backup.
  
  For more information, see Connecting Compute Cloud VMs to Cloud Backup.
- (Optional) Under Monitoring, enable the Agent for delivering metrics option to configuire delivery of metrics to Yandex Monitoring.
- (Optional) Under Placement, select a VM placement group.
Click Create VM.

The preemptible VM will appear in the list.

If you do not have the Yandex Cloud command line interface yet, install and initialize it.

The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.

View the description of the CLI command to create a preemptible VM:
```
yc compute instance create --help
```
Prepare a key pair (public and private keys) for SSH access to the preemptible VM.

Select a Linux-based public image from Yandex Cloud Marketplace, e.g., CentOS 7.

To get a list of available images using the CLI, run this command:

yc compute image list --folder-id standard-images

Result:

+----------------------+-------------------------------------+--------------------------+----------------------+--------+
|          ID          |                NAME                 |          FAMILY          |     PRODUCT IDS      | STATUS |
+----------------------+-------------------------------------+--------------------------+----------------------+--------+
...
| fdvk34al8k5n******** | centos-7-1549279494                 | centos-7                 | dqni65lfhvv2******** | READY  |
| fdv7ooobjfl3******** | windows-2016-gvlk-1548913814        | windows-2016-gvlk        | dqnnc72gj2is******** | READY  |
| fdv4f5kv5cvf******** | ubuntu-1604-lts-1549457823          | ubuntu-1604-lts          | dqnnb6dc7640******** | READY  |
...
+----------------------+-------------------------------------+--------------------------+----------------------+--------+

Create a preemptible VM in the default folder:
```
yc compute instance create \
  --name first-preemptible-instance \
  --zone ru-central1-a \
  --network-interface subnet-name=default-a,nat-ip-version=ipv4 \
  --preemptible \
  --create-boot-disk image-folder-id=standard-images,image-family=centos-7 \
  --ssh-key ~/.ssh/id_ed25519.pub
```
Note

If you are using the CLI version 0.92.0 or lower, then in the command, you must also specify the VM platform: --platform standard-v3. You can find out the CLI version using the yc version command and install the latest version using the yc components update command.

Where:
- --name: Name of the preemptible VM. The naming requirements are as follows:
  - The name must be from 3 to 63 characters long.
  - It may contain lowercase Latin letters, numbers, and hyphens.
  - The first character must be a letter and the last character cannot be a hyphen.
  Note
  
  The VM name is used to generate an internal FQDN only once: when creating a VM. If the internal FQDN is important to you, choose an appropriate name for the VM at the creation stage.
- --zone: Availability zone matching the selected subnet.
- --network-interface: VM network interface settings:
  - subnet-name: Name of the selected subnet.
  - nat-ip-version=ipv4: Public IP address. To create a VM without a public IP address, disable this parameter.
  If you want to add multiple network interfaces to the VM, specify the --network-interface parameter as many times as you need. You can add up to eight network interfaces to a single VM.
- --preemptible: Select to create a preemptible VM.
- --create-boot-disk: VM boot disk settings:
  - image-family: Image family, e.g., centos-7. This option allows you to install the latest version of the OS from the specified family.
- --ssh-key: Path to the file with the public SSH key. The preemptible VM will automatically create a user named yc-user for this key.
  
  When creating a VM from a Yandex Cloud Marketplace public image, make sure to provide an SSH key to the VM. By default, SSH access with a username and password is disabled for such images.

If you don't have Terraform, install it and configure the Yandex Cloud provider.

In the configuration file, describe the parameters of the resources you want to create:
```
resource "yandex_compute_disk" "boot-disk" {
  name     = "<disk_name>"
  type     = "<disk_type>"
  zone     = "<availability_zone>"
  size     = "<disk_size>"
  image_id = "<image_ID>"
}

resource "yandex_compute_instance" "vm-1" {
  name                      = "preemptible-vm"
  allow_stopping_for_update = true
  platform_id               = "standard-v3"
  zone                      = "<availability_zone>"

  resources {
    cores  = <number_of_vCPU_cores>
    memory = <RAM_in_GB>
  }

  boot_disk {
    disk_id = yandex_compute_disk.boot-disk.id
  }

  network_interface {
    subnet_id = "${yandex_vpc_subnet.subnet-1.id}"
    nat       = true
  }

  metadata = {
    ssh-keys = "<username>:<SSH_key_contents>"
  }

  scheduling_policy {
    preemptible = true
  }
}

resource "yandex_vpc_network" "network-1" {
  name = "network1"
}

resource "yandex_vpc_subnet" "subnet-1" {
  name       = "subnet1"
  zone       = "<availability_zone>"
  network_id = "${yandex_vpc_network.network-1.id}"
}
```
Where:
- yandex_compute_disk: Boot disk description:
  - name: Disk name.
  - type: Disk type.
  - zone: Availability zone the disk will be in.
  - size: Disk size in GB.
  - image_id: ID of the image to create the preemptible VM from. You can get the image ID from the list of public images.
    
    You can also view image IDs in the management console when creating a VM or on the image page in Cloud Marketplace, under Product IDs.
- yandex_compute_instance: Description of the preemptible VM:
  - name: Name of the preemptible VM.
  - allow_stopping_for_update: Allow a VM instance to stop to make changes. Set true if you plan to change the network settings, computing resources, disks, or file storage for your VM using Terraform. The default value is false.
  - platform_id: Platform.
  - zone: Availability zone to host the preemptible VM.
  - resources: Number of vCPU cores and the amount of RAM available to the preemptible VM. The values must match the selected platform.
  - boot_disk: Boot disk settings. Specify the disk ID.
  - network_interface: VM's network interface settings. Specify the ID of the selected subnet. To automatically assign a public IP address to the VM, set nat = true.
    
    If you want to add multiple network interfaces to the VM, specify the network_interface section as many times as you need. You can add up to eight network interfaces to a single VM.
  - metadata: In metadata, provide the public key for SSH access to the preemptible VM. For more information, see VM metadata.
  - scheduling_policy: Scheduling policy. To create a preemptible VM, select preemptible = true.
- yandex_vpc_network: Description of the cloud network.
- yandex_vpc_subnet: Description of the subnet to connect your preemptible VM to.
Note

If you already have suitable resources, such as a cloud network and subnet, you do not need to describe them again. Use their names and IDs in the appropriate parameters.

For more information about the resources you can create with Terraform, see the provider documentation.
Create resources:
1. In the terminal, change to the folder where you edited the configuration file.
2. Make sure the configuration file is correct using the command:
```
terraform validate
```
  If the configuration is correct, the following message is returned:
```
Success! The configuration is valid.
```
3. Run the command:
```
terraform plan
```
  The terminal will display a list of resources with parameters. No changes are made at this step. If the configuration contains errors, Terraform will point them out.
4. Apply the configuration changes:
```
terraform apply
```
5. Confirm the changes: type yes in the terminal and press Enter.
All the resources you need will then be created in the specified folder. You can check the new resources and their configuration using the management console.

Use the create REST API method for the Instance resource or the InstanceService/Create gRPC API call.

When a VM is created, it is assigned an IP address and hostname (FQDN). This data can be used for SSH access.

You can make a public IP address static. For more information, see Making a VM's public IP address static.

Changing a VM's type

To change the type of a VM, for example, make it preemptible:

Management console

CLI

Terraform

API

In the management console, select the folder where the preemptible VM is located.
In the list of services, select Compute Cloud.
In the left-hand panel, select Virtual machines.
In the line with the appropriate VM, click and select Stop.
In the window that opens, click Stop. The VM status will change to Stopped.
In the line with the appropriate VM, click and select Edit.
Under Computing resources, disable the Preemptible option.
Click Save changes.
At the top right, click Start.
In the window that opens, click Start.

If you do not have the Yandex Cloud command line interface yet, install and initialize it.

The folder specified in the CLI profile is used by default. You can specify a different folder using the --folder-name or --folder-id parameter.

See the description of the CLI command to stop a VM:
```
yc compute instance stop --help
```

Get a list of all VMs in the default folder:

yc compute instance list

Result:

+----------------------+-----------------+---------------+---------+----------------------+
|          ID          |       NAME      |    ZONE ID    | STATUS  |     DESCRIPTION      |
+----------------------+-----------------+---------------+---------+----------------------+
| fhm0b28lgfp4******** | first-instance  | ru-central1-a | RUNNING | my first vm via CLI  |
| fhm9gk85nj7g******** | second-instance | ru-central1-a | RUNNING | my second vm via CLI |
+----------------------+-----------------+---------------+---------+----------------------+

Select the ID or NAME of the VM, e.g., first-instance.

Stop the VM:

yc compute instance stop <VM_name_or_ID>

Result:

done (15s)

Edit the VM parameters:

yc compute instance update <VM_name_or_ID> \
  --preemptible=false

Result:

done (1s)
id: fhm0b28lgfp4********
folder_id: b1ghgf288nvg********
...
network_settings:
  type: STANDARD
placement_policy: {}

Start the VM again:

yc compute instance start <VM_name_or_ID>

Result:

done (11s)
id: fhm0b28lgfp4********
folder_id: b1ghgf288nvg********
...
network_settings:
  type: STANDARD
placement_policy: {}

If you don't have Terraform, install it and configure the Yandex Cloud provider.

In the configuration file, find a description of the scheduling policy of the VM you want to make preemptible:
```
scheduling_policy {
  preemptible = true
}
```
Delete the scheduling_policy field with the preemptible = true value.

For more information about the resources you can create with Terraform, see the provider documentation.
Make sure the configuration files are correct.
1. In the command line, go to the folder where you created the configuration file.
2. Run a check using this command:
```
terraform plan
```
If the configuration is described correctly, the terminal will display a list of created resources and their parameters. If the configuration contains any errors, Terraform will point them out.
Deploy cloud resources.
1. If the configuration does not contain any errors, run this command:
```
terraform apply
```
2. Confirm that you want to create the resources.
All the resources you need will then be created in the specified folder. You can check the new resources and their configuration using the management console.

Use the update REST API method for the Instance resource or the InstanceService/Update gRPC API call. Under schedulingPolicy in the request body, specify "preemptible": false.

This will affect your bill for the VM usage. More about VM pricing.

Making a VM preemptible

Creating a preemptible VM

Changing a VM's type

See also

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Making a VM preemptible

Creating a preemptible VMCreating a preemptible VM

Changing a VM's typeChanging a VM's type

See alsoSee also

Was the article helpful?

Creating a preemptible VM

Changing a VM's type

See also