[Yandex Cloud documentation](../../../index.md) > [Yandex Cloud Functions](../../index.md) > [Step-by-step guides](../index.md) > Managing a function > Mounting external resources to a function file system > Mounting an ephemeral disk

# Mounting an ephemeral disk in a function

{% note info %}

This feature is in the [Preview](../../../overview/concepts/launch-stages.md) stage. To get access, contact [tech support](https://center.yandex.cloud/support) or your account manager.

{% endnote %}

{% list tabs group=instructions %}

- Management console {#console}

  1. In the [management console](https://console.yandex.cloud), navigate to the folder containing the function.
  1. Navigate to **Cloud Functions**.
  1. Select the function.
  1. In the left-hand menu, select ![image](../../../_assets/console-icons/pencil-to-square.svg) **Editor**.
  1. Under **Mounted ephemeral disk**:

      1. Click **Add ephemeral disk**.
      1. Specify the following:

          * **Mount point**: Name of the mount point. The directory with the mounted ephemeral disk will be accessible at `/function/storage/<mount_point>`.
          * **Disk size**: Amount of memory you want to allocate for the ephemeral disk you are mounting.
  1. Click **Save changes**.

- CLI {#cli}

  If you do not have the Yandex Cloud CLI yet, [install and initialize it](../../../cli/quickstart.md#install).

  The folder used by default is the one specified when [creating](../../../cli/operations/profile/profile-create.md) the CLI profile. To change the default folder, use the `yc config set folder-id <folder_ID>` command. You can also specify a different folder for any command using `--folder-name` or `--folder-id`. If you access a resource by its name, the search will be limited to the default folder. If you access a resource by its ID, the search will be global, i.e., through all folders based on access permissions.

  To mount an ephemeral disk in a function, run this command:

  ```bash
  yc serverless function version create \
    --function-name=<function_name> \
    --runtime <runtime_environment> \
    --entrypoint <entry_point> \
    --memory <RAM_size> \
    --execution-timeout <execution_timeout> \
    --source-path <path_to_ZIP_archive> \
    --service-account-id <service_account_ID> \
    --mount type=ephemeral-disk,mount-point=<mount_point>,size=<disk_size>
  ```

  Where:

  * `--function-name`: Function name.
  * `--runtime`: Runtime.
  * `entrypoint`: Entry point in `<file_name_without_extension>.<handler_name>` format.
  * `--memory`: Amount of RAM.
  * `--execution-timeout`: Maximum function execution time before timeout.
  * `--source-path`: ZIP archive with the function code and required dependencies.
  * `--service-account-id`: Service account ID.
  * `--mount`: Ephemeral disk mount settings:
    * `type=ephemeral-disk`: Type of the file system being mounted.
    * `mount-point`: Name of the mount point. The directory with the mounted disk will be accessible at `/function/storage/<mount_point>`.
    * `size`: Ephemeral disk size in GB, e.g., `size=5GB`.

- Terraform {#tf}

  With [Terraform](https://www.terraform.io/), you can quickly create a cloud infrastructure in Yandex Cloud and manage it using configuration files. These files store the infrastructure description written in HashiCorp Configuration Language (HCL). If you change the configuration files, Terraform automatically detects which part of your configuration is already deployed, and what should be added or removed.
  
  Terraform is distributed under the [Business Source License](https://github.com/hashicorp/terraform/blob/main/LICENSE). The [Yandex Cloud provider for Terraform](https://github.com/yandex-cloud/terraform-provider-yandex) is distributed under the [MPL-2.0](https://www.mozilla.org/en-US/MPL/2.0/) license.
  
  For more information about the provider resources, see the guides on the [Terraform](https://www.terraform.io/docs/providers/yandex/index.html) website or [its mirror](../../../terraform/index.md).

  If you do not have Terraform yet, [install it and configure the Yandex Cloud provider](../../../tutorials/infrastructure-management/terraform-quickstart.md#install-terraform).
  
  
  To manage infrastructure using Terraform under a service account or user accounts (a Yandex account, a federated account, or a local user), [authenticate](../../../terraform/authentication.md) using the appropriate method.

  To mount an ephemeral disk in a function:

  1. Open the Terraform configuration file and add the `mounts` section to the function description:

      ```hcl
      resource "yandex_function" "ephemeral_storage_function" {
        name               = "<function_name>"
        user_hash          = "<function_hash>"
        runtime            = "<runtime>"
        entrypoint         = "<entry_point>"
        memory             = "<RAM_size>"
        execution_timeout  = "<execution_timeout>"
        service_account_id = "<service_account_ID>"
        content {
          zip_filename = "<path_to_ZIP_archive>"
        }

        mounts {
          name = "<mount_point>"
          ephemeral_disk {
            size_gb = <disk_size>
          }
        }
      }
      ```

      Where:

      * `mounts`: Ephemeral disk mount settings:
        * `name`: Name of the mount point. The directory with the mounted disk will be accessible at `/function/storage/<mount_point>`.
        * `size_gb`: Ephemeral disk size in GB, e.g., `size=5GB`.

      For more on the properties of the `yandex_function` resource, see [this provider guide](../../../terraform/resources/function.md).

  1. Apply the changes:

     1. In the terminal, navigate to the configuration file directory.
     1. Make sure the configuration is correct using this command:
     
        ```bash
        terraform validate
        ```
     
        If the configuration is valid, you will get this message:
     
        ```bash
        Success! The configuration is valid.
        ```
     
     1. Run this command:
     
        ```bash
        terraform plan
        ```
     
        You will see a list of resources and their properties. No changes will be made at this step. Terraform will show any errors in the configuration.
     1. Apply the configuration changes:
     
        ```bash
        terraform apply
        ```
     
     1. Type `yes` and press **Enter** to confirm the changes.

  You can check the function update and its settings using the [management console](https://console.yandex.cloud) or this [CLI](../../../cli/quickstart.md) command:

  ```bash
  yc serverless function version get <function_version_ID>
  ```

- API {#api}

  To mount an ephemeral disk in a function, use the [createVersion](../../functions/api-ref/Function/createVersion.md) REST API method for the [Function](../../functions/api-ref/Function/index.md) resource or the [FunctionService/CreateVersion](../../functions/api-ref/grpc/Function/createVersion.md) gRPC API call.

{% endlist %}

## Useful links {#see-also}

* [Mounting external resources to a function file system](../../concepts/mounting.md)
* [Mounting external resources to a container file system](../../../serverless-containers/concepts/mounting.md)