Virtualization

The Virtualization section allows users to set up Virtual Machines (VMs) to run alongside TrueNAS. Delegating processes to VMs reduces the load on the physical system, which means users can utilize additional hardware resources. Users can customize six different segments of a VM when creating one in TrueNAS SCALE.

A virtual machine (VM) is an environment on a host computer that you can use as if it is a separate, physical computer. Users can use VMs to run multiple operating systems simultaneously on a single computer. Operating systems running inside a VM see emulated virtual hardware rather than the host computer physical hardware. VMs provide more isolation than Jails but also consume more system resources.

A virtual machine (VM) is an environment on a host computer that you can use as if it is a separate, physical computer. Users can use VMs to run multiple operating systems simultaneously on a single computer. Operating systems running inside a VM see emulated virtual hardware rather than the host computer physical hardware. VMs provide more isolation than Jails but also consume more system resources.

Before creating a VM, obtain an installer .iso or image file for the OS you intend to install, and create a zvol on a storage pool that is available for both the virtual disk and the OS install file.

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

1. Select the operating system you want to use 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.

2. Change other Operating System settings per 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 Enable Display to enable a SPICE Virtual Network Computing (VNC) remote connection for the VM. The Bind and Password fields display. If Enable Display is selected:

   Enter a display Password

   Use the dropdown menu to change the default IP address in Bind if you want to use a specific address as the display network interface, otherwise leave it set to 0.0.0.0. The Bind menu populates any existing logical interfaces, such as static routes, configured on the system. Bind cannot be edited after VM creation.

   Click Next.

3. Enter the CPU and memory settings for your VM.

   

   If you selected Windows as the Guest Operating System, the Virtual CPUs field displays a 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.

4. Configure disk 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.

5. Configure the network interface.

   

   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, or select VirtIO if the guest operating system supports para-virtualized network drivers.

   Select the network interface card to use from the Attach NIC dropdown list.

   Click Next.

6. Upload installation media for the operating system you selected.

   

   You can create the VM without an OS installed. To add it either type the path or browse to the location and select it.

   To upload an iso select Upload New Image File and either enter the path or browse to the location of the file.

   

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

7. Specify a GPU.

   

   The VirtIO network interface requires a guest OS that supports VirtIO para-virtualized network drivers.

   iXsystems does not have a list of approved GPUs at this time but does have drivers and basic support for the list of nvidia Supported Products.

8. Confirm your VM settings, then click Save.

After creating the VM, you can add or remove virtual devices.

Click on the VM row on the Virtual Machines screen to expand it and show the options, then click device_hub Devices.

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.

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 using a SPICE client, or by installing a 3rd party remote desktop server inside your VM. SPICE clients are available from the SPICE Protocol site.

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

Use the State 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 State toggle and stop Stop button might not function as expected. The State 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, vanilla 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, to connect to a TrueNAS data share, for example, 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.

To create a bridge interface for the VM to use if you have only one physical interface, 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.

• Adding and Managing VM Devices: Provides instructions on adding or managing devices used by VMs.
  
  
• Accessing NAS From a VM: Provides instructions on how to create a bridge interface for the VM and provides Linux and Windows examples.