> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vast.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Virtual Machines

> Learn how Vast.ai virtual machines (VMs) provide full Linux instances with init manager support, process tracing, and nested containerization for advanced workloads.

Vast.ai offers full virtual machines (VMs) in addition to [Docker-based instances](/guides/instances/docker-environment). VMs provide a complete Linux environment, making them ideal for workloads that require init managers, nested containerization, or process tracing.

## Feature Comparison

VMs offer capabilities not available in Docker-based instances:

* **Init manager support** (e.g., `systemd`), required for running Docker, Kubernetes, Snap, or other containerization tools inside your instance
* **Process tracing** (`ptrace`) support

However, VMs come with some trade-offs:

* Slower creation and boot times
* Higher disk overhead
* Smaller selection of available machines
* Fewer preconfigured templates
* Only SSH launch mode is currently supported

## Creating a VM

<Warning>
  Make sure you have added your SSH keys to your [Account page](https://cloud.vast.ai/account/) before creating a VM. SSH keys cannot be edited on running VMs, and SSH is currently the only supported connection method.
</Warning>

Use one of the templates below to get started. These templates automatically filter for VM-capable machines and will launch a VM when you rent:

| Template                                                                                                     | Description                                 | Provides     | Use Cases                                               |
| ------------------------------------------------------------------------------------------------------------ | ------------------------------------------- | ------------ | ------------------------------------------------------- |
| [Ubuntu 22.04 VM](https://cloud.vast.ai/?ref_id=62897\&creator_id=62897\&name=Ubuntu%2022.04%20VM)           | Ubuntu 22.04 server with CLI access         | CUDA, Docker | Docker Compose applications, CUDA performance profiling |
| [Ubuntu Desktop (VM)](https://cloud.vast.ai/?ref_id=62897\&creator_id=62897\&name=Ubuntu%20Desktop%20\(VM\)) | Ubuntu desktop with a graphical environment | CUDA, Docker | GUI applications, visual development workflows          |

<Note>
  Environment variables in VMs are written to `/etc/environment`.
</Note>

## Customizing VM Templates

VM images are packaged as Docker images from the `docker.io/vastai/kvm` repository. All VM templates must use one of these images, specified with the fully qualified name (e.g., `docker.io/vastai/kvm:ubuntu_terminal`).

<Tip>
  Add `vms_enabled=true` to the **Extra Filters** field of the template to filter for machines that support VMs.
</Tip>

### Docker Options

VM templates support the following flags in the **Docker options** field, which behave the same as in Docker-based instances:

| Option                    | Example                         | Description                                 |
| ------------------------- | ------------------------------- | ------------------------------------------- |
| **Environment variables** | `-e JUPYTER_DIR=/ -e TEST=OK`   | Written to `/etc/environment` inside the VM |
| **Ports**                 | `-p 8081:8081 -p 8082:8082/udp` | Expose additional ports                     |

For more details on these options, see [Docker Environment](/guides/instances/docker-environment).

### Launch Modes

Currently only **SSH** is supported. See the [SSH guide](/guides/instances/connect/ssh) for connection details.

## Differences from Docker-Based Instances

* **Data copy**: The cloud copy utility for VMs only supports migrating the entire VM, individual folder copies are not available.
* **Copy scope**: Copy is only supported between two VMs, not between VMs and external cloud storage providers.
* **Copy command**: Use `vastai copy $SRC $DEST` to copy between VMs. Note: `vastai vm copy` is not available as a CLI command.