Virtual Machines

TrueNAS has built-in virtualization capabilities that allow running multiple operating systems on a single system, maximizing hardware utilization, and consolidating workloads.

A virtual machine (VM) is a software-based computer that runs inside your TrueNAS system, and appears as a separate physical machine to the operating system installed within it. VMs use virtualized hardware components including, network interfaces, storage volumes, graphics adapters, and other devices, providing complete isolation between different operating systems and applications.

VMs offer stronger isolation than containers but require more system resources, making them ideal for running full operating systems, legacy applications, or services that need dedicated environments.

Before creating a VM:

• Obtain an installer .iso or image file for the OS you intend to install
• Create a zvol on a storage pool that is available for both the virtual disk and the OS install file.

If the VM needs to access local NAS storage, you must create a network bridge to allow communication. See Accessing TrueNAS Storage from a VM below for more information.

To create a new VM, go to Virtual Machines and click Add to open the Create Virtual Machine wizard. If you have not yet added a virtual machine to your system, clicking Add Virtual Machines opens the same wizard.

1. Configure the Operating System settings.

   a. Select the operating system for the VM from the Guest Operating System dropdown list.

   

   Compare the recommended specifications for the guest operating system with your available host system resources when allocating virtual CPUs, cores, threads, and memory size.

   b. Enter a name for the VM.

   c. (Optional) Enter a description for the VM. This can be any short text string describing how the VM is used or which operating system is configured.

   d. (Optional) Change the default settings in System Clock and Boot Method to suit your use case. Select UTC as the VM system time from the System Clock dropdown if you do not want to use the default Local setting. Select UEFI from the Boot Method dropdown, unless using an older OS that requires Legacy BIOS.

   e. (Optional) Select Enable Secure Boot to enable cryptographic verification of boot loaders, operating system kernels, and drivers during VM startup. This security feature prevents unauthorized or malicious code from running during the boot process by checking digital signatures against trusted certificates. Secure Boot is required for Windows 11 and some Linux distributions, and can be optional or unsupported for older operating systems.

   f. (Optional) Select Enable Trusted Platform Module (TPM) to provide a virtual TPM 2.0 device for the VM. TPM provides hardware-based security functions, including secure key storage, cryptographic operations, and platform attestation. This is required for Windows 11 and enhances security for other operating systems that support TPM.

   g. (Optional) Select Start on Boot to start the VM after the system is restarted or boots up.

   h. (Optional) Select Enable Display (VNC) to enable a Virtual Network Computing (VNC) remote connection for the VM. Enable Display (VNC) shows the Bind and Password fields.

   i. Select the IP address or option to use in Bind. Shows if you select Enable Display. The Bind and Password fields display. If it is selected, to change the default IP address to use a specific address as the display network interface; otherwise, leave it set to 0.0.0.0. The Bind list populates with any existing logical interfaces, such as static routes, configured on the system. You cannot edit the Bind setting after saving the VM settings.

   j. Enter a password to secure access to the virtual display in Password. The Password field shows if you select Enable Display. The login screen for the display shows a credential entry field for this password.

   Click Next.

2. Enter the CPU and Memory settings for your VM.

   

   When the Guest Operating System is set to Windows, Virtual CPUs shows the default value of 2. The VM operating system might have operational or licensing restrictions on the number of CPUs.

   Do not allocate too much memory to a VM. Activating a VM with all available memory allocated to it can slow the host system or prevent other VMs from starting.

   Leave CPU Mode set to Custom if you want to select a CPU model.

   Use Memory Size and Minimum Memory Size to specify how much RAM to dedicate to this VM. To dedicate a fixed amount of RAM, enter a value (minimum 256 MiB) in the Memory Size field and leave Minimum Memory Size empty.

   To allow for memory usage flexibility (sometimes called ballooning), define a specific value in the Minimum Memory Size field and a larger value in Memory Size. The VM uses the Minimum Memory Size for normal operations but can dynamically allocate up to the defined Memory Size value in situations where the VM requires additional memory. Reviewing available memory from within the VM typically shows the Minimum Memory Size.

   Click Next.

3. Configure Disks settings.

   

   Select Create new disk image to create a new zvol on an existing dataset.

   Select Use existing disk image to use an existing zvol for the VM.

   Select either AHCI or VirtIO from the Select Disk Type dropdown list. We recommend using AHCI for Windows VMs.

   Select the location for the new zvol from the Zvol Location dropdown list.

   Enter a value in Size (Examples: 500KiB, 500M, and 2TB) to indicate the amount of space to allocate for the new zvol.

   Click Next.

4. Configure Network Interface settings.

   

   Select the network interface type from the Adapter Type dropdown list. Select Intel e82585 (e1000) as it offers a higher level of compatibility with most operating systems.

   Select VirtIO if the guest operating system supports para-virtualized network drivers. The VirtIO network interface requires a guest OS that supports VirtIO para-virtualized network drivers.

   Select the network interface card to use from the Attach NIC dropdown list. If the VM needs to access local NAS storage, attach a network bridge interface.

   Click Next.

5. Configure Installation Media settings to upload the operating system you selected in step 1.

   

   You can create the VM without an OS installed, then edit the VM to add it later. To add the installation media, type the path or browse to select the location of the image file, and then select it.

   To upload an iso, click Upload New Image File. Enter the path or browse to select the location of the file.

   

   Click Upload to begin the upload process. After the upload finishes, click Next.

6. Specify GPU settings. When available, use a GPU previously isolated for VM use.

   

   TrueNAS does not have a list of approved GPUs at this time, but TrueNAS does support various NVIDIA, Intel, and AMD GPUs.

7. Confirm your VM settings, then click Save.

Using the Create Virtual Machine wizard configures at least one disk and NIC, and optionally a CD-ROM and display as part of the process, but you can add more devices to suit your use case. Go to Virtual Machines, then click anywhere on a VM entry to expand it and show the options for the VM.

The VM options change when the VM is running.

Click device_hub Devices to open the Devices screen for that VM. Click the more_vert icon at the right of each listed device to see device options.

The devices for the VM display as a list.

Device notes:

• A virtual machine attempts to boot from devices according to the Device Order, starting with 1000, then ascending.
• A CD-ROM device allows booting a VM from a CD-ROM image like an installation CD. The CD image must be available in the system storage.
• A Display device provides remote clients with a way to connect to VM display sessions.

See Adding and Managing VM Devices for more information.

After creating the VM and configuring devices for it, click on the VM to expand it and show the options to manage the VM.

An active VM displays options for settings_ethernet Display and keyboard_arrow_right Serial Shell connections.

When a display device is configured, remote clients can connect to VM display sessions.

If the display connection screen appears distorted, try adjusting the display device resolution.

Use the Running toggle or click stop Stop to follow a standard procedure to do a clean shutdown of the running VM. Click power_settings_new Power Off to halt and deactivate the VM, which is similar to unplugging a computer.

If the VM does not have a guest OS installed, the VM Running toggle and stop Stop button might not function as expected. The Running toggle and stop Stop buttons send an ACPI power down command to the VM operating system, but since an OS is not installed, these commands time out. Use the Power Off button instead.

After configuring the VM in TrueNAS and an OS .iso file is attached, start the VM and begin installing the operating system.

Some operating systems can require specific settings to function properly in a virtual machine. For example, plain Debian can require advanced partitioning when installing the OS. Refer to the documentation for your chosen operating system for tips and configuration instructions.

Configure VM network settings during or after installation of the guest OS. To communicate with a VM from other parts of your local network, use the IP address configured or assigned by DHCP within the VM.

To confirm network connectivity, send a ping to and from the VM and other nodes on your local network.

By default, VMs are unable to communicate directly with the host NAS. If you want to access your TrueNAS SCALE directories from a VM, for example, to connect to a TrueNAS data share, you have multiple options.

If your system has more than one physical interface, you can assign your VMs to a NIC other than the primary one your TrueNAS server uses. This method makes communication more flexible but does not offer the potential speed of a bridge.

If your system has only one physical interface, create a bridge interface for the VM to use. Stop all existing apps, VMs, and services using the current interface, edit the interface and VMs, create the bridge, and add the bridge to the VM device. See Accessing NAS from VM for more information.