$Date: 2025-08-11 19:18:47 +0200 (Mon, 11 Aug 2025) $

VBoxManage modifyvm

VBoxManage-modifyvm 1
VBoxManage-modifyvm Change settings for a virtual machine that is stopped &product-name;
`VBoxManage modifyvm` uuid vmname --name=name --groups=group,group --description=description --os-type=OS-type --icon-file=filename --memory=size-in-MB --page-fusion= on off --vram=size-in-MB --acpi= on off --ioapic= on off --hardware-uuid=UUID --cpus=CPU-count --cpu-hotplug= on off --plug-cpu=CPU-ID --unplug-cpu=CPU-ID --cpu-execution-cap=number --x86-pae= on off --x86-long-mode= on off --ibpb-on-vm-exit= on off --ibpb-on-vm-entry= on off --spec-ctrl= on off --l1d-flush-on-sched= on off --l1d-flush-on-vm-entry= on off --mds-clear-on-sched= on off --mds-clear-on-vm-entry= on off --cpu-profile= host Intel 8086 Intel 80286 Intel 80386 --x86-hpet= on off --hwvirtex= on off --triple-fault-reset= on off --apic= on off --x86-x2apic= on off --arm-gic-its= on off --paravirt-provider= none default legacy minimal hyperv kvm --paravirt-debug=key=value [,key=value...] --nested-paging= on off --large-pages= on off --x86-vtx-vpid= on off --x86-vtx-ux= on off --nested-hw-virt= on off --virt-vmsave-vmload= on off --accelerate-3d= on off --chipset= ich9 piix3 armv8virtual --iommu= none automatic amd intel --tpm-type= none 1.2 2.0 host swtpm --tpm-location=location --firmware-logo-fade-in= on off --firmware-logo-fade-out= on off --firmware-logo-display-time=msec --firmware-logo-image-path=pathname --firmware-boot-menu= disabled menuonly messageandmenu --firmware-apic= disabled apic x2apic --firmware-system-time-offset=msec --firmware-pxe-debug= on off --system-uuid-le= on off --bootX= none floppy dvd disk net --rtc-use-utc= on off --graphicscontroller= none vboxvga vmsvga vboxsvga qemuramfb --snapshot-folder= default pathname --firmware= bios efi efi32 efi64 --guest-memory-balloon=size-in-MB --default-frontend= default name --vm-process-priority= default flat low normal high --vm-execution-engine= default hm hwvirt nem native-api interpreter recompiler `VBoxManage modifyvm` uuid vmname --nicN= none null nat bridged intnet hostonly hostonlynet generic natnetwork cloud --nic-typeN= Am79C970A Am79C973 82540EM 82543GC 82545EM virtio usbnet --cable-connectedN= on off --nic-traceN= on off --nic-trace-fileN=filename --nic-propertyN=name= value --nic-speedN=kbps --nic-boot-prioN=priority --nic-promiscN= deny allow-vms allow-all --nic-bandwidth-groupN= none name --bridge-adapterN= none device-name --cloud-networkN=network-name --host-only-adapterN= none device-name --host-only-netN=network-name --intnetN=network-name --nat-networkN=network-name --nic-generic-drvN=driver-name --mac-addressN= auto MAC-address `VBoxManage modifyvm` uuid vmname --nat-netN= network default --nat-pfN= [rule-name],tcp udp,[host-IP],hostport,[guest-IP],guestport --nat-pfN=delete=rule-name --nat-tftp-prefixN=prefix --nat-tftp-fileN=filename --nat-tftp-serverN=IP-address --nat-bind-ipN=IP-address --nat-dns-pass-domainN= on off --nat-localhostreachableN= on off --nat-settingsN=[mtu] --nat-forward-broadcastN= on off --nat-enable-tftpN= on off `VBoxManage modifyvm` uuid vmname --mouse= ps2 usb usbtablet usbmultitouch usbmtscreenpluspad --keyboard= ps2 usb --uartN= off IO-base IRQ --uart-modeN= disconnected server pipe client pipe tcpserver port tcpclient hostname:port file filename device-name --uart-typeN= 16450 16550A 16750 --lpt-modeN=device-name --lptN= off IO-base IRQ --audio-controller= ac97 hda sb16 --audio-codec= stac9700 ad1980 stac9221 sb16 --audio-driver= none default null dsound was oss alsa pulse coreaudio --audio-enabled= on off --audio-in= on off --audio-out= on off --clipboard-mode= disabled hosttoguest guesttohost bidirectional --clipboard-file-transfers= enabled disabled --drag-and-drop= disabled hosttoguest guesttohost bidirectional --monitor-count=number --usb-ehci= on off --usb-ohci= on off --usb-xhci= on off --usb-rename=old-name new-name `VBoxManage modifyvm` uuid vmname --recording= on off --recording-screens= all none screen-ID[,screen-ID...] --recording-file=filename --recording-max-size=MB --recording-max-time=seconds --recording-opts= key=value[,key=value...] --recording-video-fps=fps --recording-video-rate=rate --recording-video-res=width x height `VBoxManage modifyvm` uuid vmname --vrde= on off --vrde-property=property-name=property-value --vrde-extpack= default name --vrde-port=port --vrde-address=hostip --vrde-auth-type= null external guest --vrde-auth-library= default name --vrde-multi-con= on off --vrde-reuse-con= on off --vrde-video-channel= on off --vrde-video-channel-quality=percent `VBoxManage modifyvm` uuid vmname --teleporter= on off --teleporter-port=port --teleporter-address= address empty --teleporter-password=password --teleporter-password-file= filename stdin --cpuid-portability-level=level --cpuid-set=leaf:subleaf eax ebx ecx edx --cpuid-remove=leaf:subleaf --cpuid-remove-all `VBoxManage modifyvm` uuid vmname --tracing-enabled= on off --tracing-config=string --tracing-allow-vm-access= on off `VBoxManage modifyvm` uuid vmname --usb-card-reader= on off `VBoxManage modifyvm` uuid vmname --autostart-enabled= on off --autostart-delay=seconds `VBoxManage modifyvm` uuid vmname --guest-debug-provider= none native gdb kd --guest-debug-io-provider= none tcp udp ipc --guest-debug-address= IP-Address path --guest-debug-port=port `VBoxManage modifyvm` uuid vmname --pci-attach=host-PCI-address@guest-PCI-bus-address --pci-detach=host-PCI-address `VBoxManage modifyvm` uuid vmname --testing-enabled=on off --testing-mmio=on off --testing-cfg-dwordidx=value

## Description

The `VBoxManage modifyvm` command enables you to change the properties of a registered virtual machine (VM) that is not running.

Most of these properties correspond to the VM settings that are shown in each VM's Settings dialog in the VirtualBox Manager. See . However, some settings can only be viewed and managed with the `VBoxManage` command.

You can use the `VBoxManage modifyvm` command to change VM settings only when the VM is powered off. The VM cannot be running or in saved state when you use this command.

You can use the `VBoxManage controlvm` command to dynamically change some VM machine settings while the VM is running. See .

### General Settings

The following options enable you to modify general information about your VM.

The `VBoxManage modifyvm` command supports the following options:

`--name=vmname`

  Changes the name of the VM and its related internal VM files. See .

`--groups=group`

  Changes the group membership of a VM. Group names always begin with a slash character (`/`) and can be nested. By default, VMs are members of the `/` group. A VM can be member of multiple groups, but its primary group determines the directory structure where the internal VM files are placed by default.

`--description=desc`

  Changes the optional VM description. Use a description to record details about the VM in a meaningful way. The GUI interprets HTML markup while the `VBoxManage modifyvm` command enables you include arbitrary strings that can contain multiple lines.

`--os-type=OS-type`

  Specifies the guest operating system (OS) information for the VM. Use the `VBoxManage list ostypes` command to view the OS type identifiers.

`--icon-file=filename`

  Specifies the path to the VM icon file in PNG format on the host system. The icon is shown in the VM manager UI and when running the VM with UI.

`--memory=size`

  Specifies the amount of host system RAM to allocate to the VM. The size is in MB. See .

`--page-fusion=on | off`

  Enables or disables the Page Fusion feature, which is disabled by default. Use the Page Fusion feature to minimize the memory duplication between VMs that have similar configurations and that run on the same host system. See .

`--vram=size`

  Specifies the amount of RAM to allocate to the virtual graphics card. See .

`--acpi=on | off`

  Determines whether the VM has ACPI support. See .

`--ioapic=on | off`

  Determines whether the VM has I/O APIC support. See .

`--hardware-uuid=uuid`

  Specifies the Universally Unique Identifier (UUID) to present to the guest VM in memory tables (DMI/SMBIOS), hardware, and VM properties. By default this hardware UUID is the same as the VM UUID. Cloning a VM and the teleporting feature automatically preserve the hardware UUID value. Likewise for Virtual Appliance export and import, but only if both operations are done by &product-name;.

`--cpus=CPU-count`

  Specifies the number of virtual CPUs to assign to the VM. See .

  If CPU hot-plugging is enabled, this option specifies the maximum number of virtual CPUs that can be plugged into the VMs.

`--cpu-hotplug=on | off`

  Enables or disables CPU hot-plugging. When enabled, you can dynamically add virtual CPUs to a VM or remove virtual CPUs from a VM. See .

`--plug-cpu=CPU-ID`

  Adds a virtual CPU to the VM. CPU-ID is the index of the virtual CPU to add. A valid index value is a number from `0` to the maximum number of CPUs that you configured by using the `--cpus` option.

  Only use this option if CPU hot-plugging is enabled.

`--unplug-cpu=CPU-ID`

  Removes a virtual CPU from the VM. CPU-ID is the index of the virtual CPU to remove. A valid index value is a number from `1` to the maximum number of CPUs that you configured by using the `--cpus` option.

  Only use this option if CPU hot-plugging is enabled.

  Note that you cannot remove CPU 0.

`--cpuexectioncap=percentage`

  Specifies how much CPU time a virtual CPU can use. A valid value is from `1` to `100`. A value of 50 indicates that a single virtual CPU can use up to 50% of a single host CPU.

  Use this feature with caution, it can have unexpected results including timekeeping problems and lower performance than specified. If you want to limit the resource usage of a VM it is more reliable to pick an appropriate number of VCPUs.

`--x86-pae=on | off`

  Enables or disables physical address extension (PAE). See .

`--x86-long-mode=on | off`

  Enables or disables long mode. See .

`--ibpb-on-vm-exit=on | off`

  Enables use of Indirect Branch Prediction Barrier (IBPB) on every VM exit.

`--ibpb-on-vm-entry=on | off`

  Enables use of Indirect Branch Prediction Barrier (IBPB) on every VM entry.

`--spec-ctrl=on | off`

  Enables or disables the exposure of speculation control interfaces to the guest VM. These interfaces must be available on the host system.

  Depending on the host CPU and the workload, enabling speculation control might significantly reduce performance.

`--l1d-flush-on-sched=on | off`

  Enables or disables level 1 data cache flushing when a thread is scheduled to execute guest code. See .

`--l1d-flush-on-vm-entry=on | off`

  Enables or disables level 1 data cache flushing on every VM entry. See .

`--mds-clear-on-sched=on | off`

  Enables CPU buffer clearing when a thread is scheduled to execute guest code. See .

`--mds-clear-on-vm-entry=on | off`

  Enables CPU buffer clearing on every VM entry. See .

`--cpu-profile=host | Intel 8086 | Intel 80286 | Intel 80386`

  Specifies the profile to use for guest CPU emulation. Specify a value that is based on the host system CPU (`host`) or one of the following older Intel micro-architectures: `8086`, `80286`, or `80386`.

`--x86-hpet=on | off`

  Enables or disables a High Precision Event Timer (HPET) that can replace a legacy system timer. This feature is disabled by default. Note HPET is supported on Windows versions starting with Vista.

`--hwvirtex=on | off`

  Enables or disables the use of hardware virtualization extensions in the processor of the host system. Such extensions are Intel VT-x or AMD-V.

`--triple-fault-reset=on | off`

  Enables or disables the resetting of the guest VM instead of triggering a Guru Meditation. Some guest VMs raise a triple fault to reset the CPU, so sometimes resetting the guest VM is the best outcome. This option only applies to guests that do not use symmetric multiprocessing (SMP).

`--apic=on | off`

  Enables or disables APIC. With APIC, OSes can use more than 16 interrupt requests (IRQs) to avoid IRQ sharing and to improve reliability. APIC is enabled by default. See .

`--x86-x2apic=on | off`

  Enables or disables the CPU x2APIC feature. CPU x2APIC enables an OS to run more efficiently on high core count configurations and to optimize interrupt distribution in virtualized environments. This feature is enabled by default.

  Disable this feature when the OS that runs on a host system or a guest VM is incompatible with CPU x2APIC.

`--arm-gic-its=on | off`

  Enables or disables the ITS (Interrupt Translation Service) component of the GIC (Generic Interrupt Controller). This feature is disabled by default.

`--paravirt-provider=none | default | legacy | minimal | hyperv | kvm`

  Specifies one of the following paravirtualization interfaces to provide to the guest OS:

  - `none` does not expose any paravirtualization interface.

  - `default` selects the appropriate interface based on the guest OS type when starting the VM. This is the default value used when creating new VMs.

  - `legacy` selects a paravirtual interface for VMs that were created by older &product-name; versions.

  - `minimal` is required for Mac OS X guest VMs.

  - `kvm` is recommended for Linux guest VMs. See .

  - `hyperv` is recommended for Windows guest VMs. See .

`--paravirt-debug=property=value`

  Specifies debugging properties that are specific to the paravirtualization provider configured for the specified VM. See .

`--nested-paging=on | off`

  Enables or disables the nested paging feature in the processor of the host system. This option is available only when hardware virtualization is enabled. See .

`--large-pages=on | off`

  Enables or disables the hypervisor's use of large pages, which can improve performance by up to 5%. The use of large pages reduces TLB use and overhead. This option is available only when both hardware virtualization and nested paging are enabled.

`--x86-vtx-vpid=on | off`

  Enables or disables the use of the tagged TLB (VPID) feature in the processor of your host system. This option is available only when hardware virtualization is enabled on Intel VT-x.

`--x86-vtx-ux=on | off`

  Enables or disables the use of unrestricted guest mode for executing the guest VM. This option is available only when hardware virtualization is enabled on Intel VT-x.

`--nested-hw-virt=on | off`

  Enables or disables nested virtualization. Enabling makes hardware virtualization features available to the VM. See .

`--virt-vmsave-vmload=on | off`

  If hardware virtualization is enabled and the host has an AMD CPU, this setting enables or disables the use of the virtualized vmsave/vmload host feature while executing the VM. It is enabled by default. It is recommended to leave it enabled as it has a drastic impact on performance while executing nested VMs when using the nested hardware virtualization feature. .

`--accelerate-3d=on | off`

  Enables or disables hardware 3D acceleration for the graphics adapter variants which support it. This option has an effect only when the Guest Additions are installed. See .

`--chipset=piix3 | ich9 | armv8virtual`

  Specify the Intel chipset for &product-name; to emulate. For the x86 platform, the default value is the Intel PIIX3 chipset. (`piix3`). For the ARM platform, the default value is the ARMv8Virtual chipset. (`armv8virtual`).

  Change this value only if you need to relax some of the chipset constraints. See .

`--iommu=none | automatic | amd | intel`

  Specifies the IOMMU type for &product-name; to emulate. Both Intel and AMD IOMMU emulation currently require the use of the Intel ICH9 chipset (see `--chipset` option).

  Valid values are as follows:

  - `none` – No IOMMU is present and is the default value.

  - `automatic` – An IOMMU is present but its type is automatically chosen to match the host CPU vendor when the VM is powered on.

  - `amd` – An AMD IOMMU is present.

  - `intel` – An Intel IOMMU is present.

`--tpm-type=none | 1.2 | 2.0 | host | swtpm`

  Specifies the TPM type for &product-name; to emulate.

  Valid values are as follows:

  - `none` – No TPM is present and is the default value.

  - `1.2` – A TPM conforming to the TCG specification version 1.2 is present.

  - `2.0` – A TPM conforming to the TCG specification version 2.0 is present.

  - `host` – The host TPM is passed through to the guest. May not be available on all supported host platforms.

  - `swtpm` – The VM connects to an external TPM emulation compliant to swtpm. Requires to set the TPM location to connect to (see `--tpm-location` option).

`--firmware-logo-fade-in=on | off`

  Specifies whether the BIOS logo fades in on VM startup. By default, an &product-name; logo is shown.

`--firmware-logo-fade-out=on | off`

  Specifies whether the BIOS logo fades out on VM startup.

`--firmware-logo-display-time=msec`

  Specifies the amount of time in milliseconds that the BIOS logo is visible.

`--firmware-logo-image-path=pathname`

  Replaces the existing BIOS logo with a different image. The replacement image must be an uncompressed 16, 256 or 16M color bitmap file (BMP) that does not contain color space information (Windows 3.0 format). Also ensure that the image is no larger than 640 X 480 pixels.

`--firmware-boot-menu=disabled | menuonly | messageandmenu`

  Specifies whether the BIOS permits you to select a temporary boot device. Valid values are:

  - `disabled` outputs the alternate boot device message and permits you to select a temporary boot device by pressing F12.

  - `menuonly` suppresses the alternate boot device message, but permits you to select a temporary boot device by pressing F12.

  - `messageandmenu` suppresses the alternate boot device message and prevents you from selecting a temporary boot device by pressing F12.

`--firmware-apic=x2apic | apic | disabled`

  Specifies the APIC level of the firmware. Valid values are: `x2apic`, `apic`, and `disabled`. When the value is `disabled`, neither the `apic` nor the `x2apic` version of the firmware is used.

  Note that if you specify the `x2apic` value and x2APIC is unsupported by the virtual CPU, the APIC level downgrades to `apic`, if supported. Otherwise, the APIC level downgrades to `disabled`. Similarly, if you specify the `apic` value and APIC is unsupported by the virtual CPU, the APIC level downgrades to `disabled`.

`--firmware-system-time-offset=msec`

  Specifies the time offset in milliseconds of the guest VM relative to the time on the host system. If the offset value is positive, the guest VM time runs ahead of the time on the host system.

`--firmware-pxe-debug=on | off`

  Enables or disables additional debugging output when using the Intel PXE boot ROM. The debug output is written to the release log file. See .

`--system-uuid-le=on | off`

  Enables or disables representing the system UUID in little endian form. The default value is `on` for new VMs. For old VMs the setting is `off` to keep the content of the DMI/SMBIOS table unchanged, which can be important for Windows license activation.

`--bootN=none | floppy | dvd | disk | net`

  Enables you to specify the boot device order for the VM by assigning one of the device types to each of the four boot device slots that are represented by N in the option name.

  A value of 1 for N represents the first boot device slot, and so on.

  The device types are `floppy` for floppy disks, `dvd` for DVDs or CDs, `disk` for hard disks, and `net` for a network device. A value of `none` indicates that no boot device is associated with the specified slot.

`--rtc-use-utc=on | off`

  Specifies whether the real-time clock (RTC) uses coordinated universal time (UTC). See .

`--graphicscontroller=none | vboxvga | vmsvga | vboxsvga`

  Specifies the graphics controller type to use. See .

`--snapshot-folder=default | pathname`

  Specifies the name of the VM's snapshot storage folder. If you specify `default`, the folder name is `Snapshots/` in the machine folder.

`--firmware=bios | efi | efi32 | efi64`

  Specifies the firmware used to boot the VM. Valid values are: `bios`, `efi`, `efi32`, or `efi64`. Use EFI values with care.

  By default, BIOS firmware is used.

`--guest-memory-balloon=size`

  Specifies the size of the guest memory balloon. The guest memory balloon is the memory allocated by the Guest Additions from the guest OS and returned to the hypervisor for use by other VMs. Specify size in megabytes. The default value is `0` megabytes. See .

`--default-frontend=default | name`

  Specifies the default frontend to use when starting the specified VM. If you specify `default`, the VM is shown in a window on the user's desktop. See .

`--vm-process-priority=default | flat | low | normal | high`

  Specifies the priority scheme of the VM process to use when starting the specified VM and while the VM runs.

  The following valid values are:

  - `default` – Default process priority determined by the OS.

  - `flat` – Assumes a scheduling policy which puts the process at the default priority and with all threads at the same priority.

  - `low` – Assumes a scheduling policy which puts the process mostly below the default priority of the host OS.

  - `normal` – Assume a scheduling policy which shares the CPU resources fairly with other processes running with the default priority of the host OS.

  - `high` – Assumes a scheduling policy which puts the task above the default priority of the host OS. This policy might easily cause other tasks in the system to starve.

### Networking Settings

The following options enable you to modify networking on your VM. With all these options, N is an integer greater than zero that represents the particular virtual network adapter to configure.

`--nicN=none | null | nat | natnetwork | bridged | intnet | hostonly | generic`

  Configures the network type used by each virtual network card in the VM.

  The following valid values correspond to the modes described in :

  - `none` – No networking present

  - `null` – Not connected to the host system

  - `nat` – Use network address translation (NAT)

  - `natnetwork` – Use a NAT network

  - `bridged` – Use bridged networking

  - `intnet` – Use internal networking

  - `hostonly` – Use host-only networking

  - `generic` – Access rarely used sub-modes

`--nic-typeN=Am79C970A | Am79C973 | 82540EM | 82543GC | 82545EM | virtio | usbnet`

  Identifies the type of networking hardware that &product-name; presents to the guest VM for the specified virtual network card. See .

  Valid values are as follows:

  - `Am79C970A` represents the AMD PCNet PCI II.

  - `Am79C973` represents the AMD PCNet FAST III, which is the default value.

  - `82540EM` represents the Intel PRO/1000 MT Desktop.

  - `82543GC` represents the Intel PRO/1000 T Server.

  - `82545EM` represents the Intel PRO/1000 MT Server.

  - `virtio` represents a paravirtualized network adapter.

  - `usbnet` represents an Ethernet over USB network adapter.

`--cable-connectedN=on | off`

  Temporarily disconnects a virtual network interface, as if you pull a network cable from a physical network card. You might use this option to reset certain software components in the VM.

`--nic-traceN=on | off`

  Enables or disables network tracing for the specified virtual network card.

`--nic-trace-fileN=filename`

  Specifies the absolute path of the file in which to write trace log information. Use this option if network tracing is enabled.

`--nic-propertyN=name=value`

  Enables you to set property values and pass them to rarely used network backends. To use this option, you must also use the `--nic-generic-drv` option.

  These properties are specific to the backend engine and differ between the UDP Tunnel and the VDE backend drivers. For property examples, see .

`--nic-speedN=kbps`

  Specifies the throughput rate in kilobits per second for rarely used networking sub-modes such as VDE network and UDP Tunnel. Use this option only if you used the `--nic` option to enable generic networking for the specified virtual network card.

`--nic-boot-prioN=priority`

  Assigns a priority to each NIC that determines the order in which that NIC is used to perform a PXE network boot. The priority value is an integer in the range from `0` to `4`. Priority `0`, which is the default value, is the lowest priority. Priority `1` is the highest priority, and priorities `3` and `4` are lower.

  This option has an effect only when using the Intel PXE boot ROM.

`--nic-promiscN=deny | allow-vms | allow-all`

  Enables you to specify whether to deny or allow promiscuous mode for the specified VM virtual network card. This option is relevant only for bridged networking. Valid values are as follows:

  - `deny` hides any traffic that is not intended for the VM. This is the default value.

  - `allow-vms` hides all host traffic from the VM, but allows the VM to see traffic to and from other VMs.

  - `allow-all` allows the VM to see all traffic.

`--nic-bandwidth-groupN=none | name`

  Adds or removes a bandwidth group assignment to the specified virtual network interface. Valid values are as follows:

  - `none` removes any current bandwidth group assignment from the specified virtual network interface.

  - name adds a bandwidth group assignment to the specified virtual network interface.

  See .

`--bridge-adapterN=none | device-name`

  Specifies the host interface to use for the specified virtual network interface. See . Use this option only if you used the `--nic` option to enable bridged networking for the specified virtual network card.

`--host-only-adapterN=none | device-name`

  Specifies which host-only networking interface to use for the specified virtual network interface. See . Use this option only if you used the `--nic` option to enable host-only networking for the specified virtual network card.

`--intnetN=network-name`

  Specifies the name of the internal network. See . Use this option only if you used the `--nic` option to enable internal networking for the specified virtual network card.

`--nat-networkN=network-name`

  Specifies the name of the NAT network to which this adapter is connected. Use this option only if the networking type is `natnetwork`, not `nat`.

`--nic-generic-drvN=backend-driver`

  Enables you to access rarely used networking sub-modes, such as VDE networks and UDP Tunnel. Use this option only if you used the `--nic` option to enable generic networking for a virtual network card.

`--mac-addressN=auto | MAC-address`

  Specifies the MAC address of the specified network adapter on the VM. By default, &product-name; assigns a random MAC address to each network adapter at VM creation.

### NAT Networking Settings

The following options use N to specify the particular virtual network adapter to modify.

`--nat-netN=default | network`

  Specifies the IP address range to use for this network. See . Use this option only if the networking type is `nat`, not `natnetwork`.

`--nat-pfN=[name],tcp | udp,[host-IP],hostport,[guest-IP],guestport`

  Specifies the NAT port-forwarding rule to use. See .

`--nat-pfN=delete name`

  Specifies the NAT port-forwarding rule to delete. See .

`--nat-tftp-prefixN=prefix`

  Specifies a prefix to use for the built-in TFTP server. For example, you might use a prefix to indicate where the boot file is located. See and .

`--nat-tftp-fileN=boot-file`

  Specifies the name of the TFT boot file. See .

`--nat-tftp-serverN=tftp-server`

  Specifies the address of the TFTP server from which to boot. See .

`--nat-bind-ipN=IP-address`

  Specifies an alternate IP address to which the NAT engine binds. See . By default, &product-name;'s NAT engine routes TCP/IP packets through the default interface assigned by the host's TCP/IP stack.

`--nat-dns-pass-domainN=on | off`

  Specifies whether the built-in DHCP server passes the domain name for network name resolution.

`--nat-localhostreachableN=on | off`

  Specifies whether the NAT engine allows traffic from the guest directed to 10.0.2.2 to pass to the host's loopback interface, i.e. localhost or 127.0.0.1.

`--nat-settingsN=[mtu]`

  Specifies values for tuning NAT performance. See .

### Other Hardware Settings

The following options enable you to configure other hardware, such as the serial port, monitor, audio device, USB ports, and the clipboard, and drag-and-drop features.

`--mouse=ps2 | usb | usbtablet | usbmultitouch | usbmtscreenpluspad`

  Specifies the mode of the mouse to use in the VM. Valid values are: `ps2`, `usb`, `usbtablet`, `usbmultitouch` and `usbmtscreenpluspad`.

`--keyboard=ps2 | usb`

  Specifies the mode of the keyboard to use in the VM. Valid values are: `ps2` and `usb`.

`--uartN=off | I/O-base IRQ`

  Configures virtual serial ports for the VM. N represents the serial port to modify. Valid values are `off` to disable the port or an I/O base address and IRQ. For information about the traditional COM port I/O base address and IRQ values, see .

`--uart-modeN=mode`

  Specifies how &product-name; connects the specified virtual serial port to the host system that runs the VM. See .

  Ensure that you first configure the virtual serial port by using the `--uartN` option.

  Specify one of the following connection modes for each port:

  - `disconnected` indicates that even though the serial port is shown to the guest VM, it is not connected. This state is like a physical COM port without a cable attached.

  - `server` pipe-name creates the specified named pipe or local domain socket on the host system and connects the virtual serial device to it.

    On a Windows host system, pipe-name is a named pipe that has a name that uses the following form: `\\.\pipe\pipe-name`.

    On a Linux host system, pipe-name is a local domain socket.

  - `client` pipe-name connects the virtual serial device to the specified named pipe or local domain socket.

    Note that the named pipe or local domain socket must already exist.

  - `tcpserver` port creates a TCP socket with the specified TCP port on the host system and connects the virtual serial device to it.

    For UNIX-like systems, use ports over 1024 for non-root users.

  - `tcpclient` hostname:port connects the virtual serial device to the TCP socket.

    Note that the TCP socket must already exist.

  - `file` filename redirects the serial port output to the specified raw file. Ensure that filename is the absolute path of the file on the host system.

  - device-name: specifies the device name of a physical hardware serial port on the specified host system to which the virtual serial port connects.

    Use this mode to connect a physical serial port to a VM.

    On a Windows host system, the device name is a COM port such as `COM1`. On a Linux host system, the device name is similar to `/dev/ttyS0`.

`--uart-typeN=UART-type`

  Configures the UART type for the specified virtual serial port (N). Valid values are `16450`, `16550A`, and `16750`. The default value is `16550A`.

`--lpt-modeN=device-name`

  Specifies the device name of the parallel port to use.

  For a Windows host system, use a device name such as `lpt1`. For a Linux host system, use a device name such as `/dev/lp0`.

`--lptN=I/O-base IRQ`

  Specifies the I/O base address and IRQ of the parallel port.

  You can view the I/O base address and IRQ that the VM uses for the parallel port in the Device Manager.

`--audio-controller=controller-type`

  Specifies the audio controller to be used with the VM. Valid audio controller type values are: `ac97`, `hda`, and `sb16`.

`--audio-codec=codec-type`

  Specifies the audio codec to be used with the VM. Valid audio codec type values are: `stac9700`, `ad1980`, `stac9221`, and `sb16`.

`--audio-driver=type`

  Specifies whether which audio driver (backend) to use. `none`, `default`, `null`, `dsound`, `was`, `oss`, `alsa`, `pulse`, and `coreaudio`.

  Note that the audio driver are dependent on the host operating system. Use the `VBoxManage modifyvm` command usage output to determine the supported audio types for your host system.

  For maximum interoperability between hosts, the default audio driver can be used. The VM will then automatically select the most appropriate audio driver for the current host available.

`--audio-enabled=on|off`

  Specifies whether to enable or disable audio for the VM.

  This option has precedence over the --audio-on and --audio-off options, i.e. turning off audio via this option will turn off both, input and output, audio.

`--audio-in=on|off`

  Specifies whether to enable or disable audio capture from the host system.

`--audio-out=on|off`

  Specifies whether to enable or disable audio playback from the guest VM.

`--clipboard-mode=value`

  Specifies how to share the guest VM or host system OS's clipboard with the host system or guest VM, respectively. Valid values are: `disabled`, `hosttoguest`, `guesttohost`, and `bidirectional`. See .

  The clipboard feature is available only if you have the Guest Additions be installed in the VM.

`--clipboard-file-transfers=value`

  Specifies whether file transfers via clipboard between the guest VM and the host are enabled or not. Valid values are: `disabled`, `enabled`. Depends on the current clipboard mode being set.

  This clipboard file transfer feature is available only if you have the Guest Additions be installed in the VM.

`--drag-and-drop=value`

  Specifies how to use the drag and drop feature between the host system and the VM. Valid values are: `disabled`, `hosttoguest`, `guesttohost`, and `bidirectional`. See .

  The drag and drop feature is available only if you have the Guest Additions be installed in the VM.

`--monitor-count=count`

  Enables you to configure multiple monitors. See .

`--usb-ohci=on | off`

  Enables or disables the VM's virtual USB 1.1 controller. See .

`--usb-ehci=on | off`

  Enables or disables the VM's virtual USB 2.0 controller. See .

`--usb-xhci=on | off`

  Enables or disables the VM's virtual USB 3.0 controller. This is the most efficient option if the VM supports it. See .

`--usb-rename=old-name new-name`

  Rename's the VM's virtual USB controller from old-name to new-name.

### Recording Settings

The following options enable you to modify settings for video recording, audio recording, or both.

`--recording=on | off`

  Enables or disables the recording of a VM session into a WebM or VP8 file. When set to `on`, recording begins when the VM session starts.

`--recording-screens=all | none | screen-ID[,screen-ID...`

  Enables you to specify the VM screens to record. The recording for each screen is output to its own file. Valid values are: `all`, which records all screens, `none`, which records no screens, or one or more specified screens.

`--recording-file=filename`

  Specifies the name of the file in which to save the recording.

`--recording-max-size=MB`

  Specifies the maximum size of the recorded video file in megabytes. When the file reaches the specified size, recording stops. If the value is `0`, recording continues until you manually stop recording.

`--recording-max-time=seconds`

  Specifies the maximum amount of time to record in seconds. When the specified time elapses, recording stops. If the value is `0`, recording continues until you manually stop recording.

`--recording-opts=keyword=value`

  Specifies additional video-recording properties as a comma-separated property keyword-value list. For example, `foo=bar,a=b`.

  Only use this option if you are an advanced user. For information about keywords, see the &product-name; Programming Guide and Reference.

`--recording-video-fps=fps`

  Specifies the maximum number of video frames per second (FPS) to record. The recording ignores any frames that have a higher frequency. When you increase the FPS, fewer frames are ignored but the recording and the size of the recording file increases.

`--recording-video-rate=bit-rate`

  Specifies the bit rate of the video in kilobits per second. When you increase the bit rate, the recording appearance improves and the size of the recording file increases.

`--recording-video-res=widthxheight`

  Specifies the video resolution (width and height) of the recorded video in pixels.

### Remote Machine Settings

The following options enable you to modify the VirtualBox Remote Desktop Extension (VRDE) behavior.

`--vrde=on | off`

  Enables or disables the VRDE server.

`--vrde-property=TCP/Ports=port`

  port is the port or port range to which the VRDE server binds. The `default` or `0` value uses port `3389`, which is the standard RDP port.

  See also the `--vrde-port` option description.

`--vrde-property=TCP/Address=IP-address`

  IP-address is the IP address of the host network interface to which the VRDE server binds. When specified, the server accepts connections only on the host network interface at that IP address.

  See also the `--vrde-address` option description.

`--vrde-property=VideoChannel/Enabled=value`

  Specifies whether the VRDP video channel is on or off. `1` means `on` and `0` means `off`. See .

`--vrde-property=Quality=value`

  Specifies a value between 10% and 100%, inclusive, that represents the JPEG compression level on the VRDE server video channel. A lower value produces lower JPEG quality but higher compression. See .

`--vrde-property=DownscaleProtection=value`

  Enables or disables the video downscale protection feature. Valid values are `1` to enable the feature and `0` to disable the feature.

  When this feature is enabled, &product-name; determines whether to display the video:

  - When the video size equals the size of the shadow buffer, the video is considered to be full screen and is displayed.

  - When the video size is between full screen and the downscale threshold, the video is not displayed. Such a video might be an application window, which is unreadable when downscaled.

  When this feature is disabled, an attempt is always made to display a video.

`--vrde-property=Client/DisableDisplay=1`

  Disables the display VRDE server feature.

  To re-enable a feature, assign an empty value. For example, to re-enable the display feature, specify the `VBoxManage modifyvm --vrde-property=Client/DisableDisplay=` command. See .

`--vrde-property=DisableInput=1`

  Disables the input VRDE server feature.

`--vrde-property=DisableAudio=1`

  Disables the audio VRDE server feature.

`--vrde-property=DisableUSB=1`

  Disables the USB VRDE server feature.

`--vrde-property=Client/DisableClipboard=1`

  Disables the clipboard VRDE server feature. To re-enable the feature, assign an empty value. See .

`--vrde-property=DisableUpstreamAudio=1`

  Disables the upstream audio VRDE server feature. To re-enable the feature, assign an empty value. See .

`--vrde-property=Client/DisableRDPDR=1`

  Disables the RDP device redirection for smart cards VRDE server feature. To re-enable this feature, assign an empty value.

`--vrde-property=H3DRedirect/Enabled=1`

  Enables the 3D redirection VRDE server feature. To disable this feature, assign an empty value.

`--vrde-property=Security/Method=value`

  Specifies the following information that is required for a connection:

  - `Negotiate` indicates that both Enhanced (TLS) and Standard RDP Security connections are permitted. The security method is negotiated with the client. This is the default value.

  - `RDP` indicates that only Standard RDP Security is accepted.

  - `TLS` indicates that only Enhanced RDP Security is accepted. The client must support TLS.

  See .

`--vrde-property=ServerCertificate=value`

  Specifies the absolute path to the server certificate. See .

`--vrde-property=ServerPrivateKey=value`

  Specifies the absolute path to the server private key. See .

`--vrde-property=CACertificate=value`

  Specifies the absolute path to the CA self-signed certificate. See .

`--vrde-property Audio/RateCorrectionMode=value`

  Specifies the audio connection mode or the path to the audio log file. Valid values are as follows:

  - `VRDP_AUDIO_MODE_VOID` is no mode. Use this value to unset any set audio mode.

  - `VRDP_AUDIO_MODE_RC` is the rate correction mode.

  - `VRDP_AUDIO_MODE_LPF` is the low pass filter mode.

  - `VRDP_AUDIO_MODE_CS` is the client sync sync mode to prevent an underflow or overflow of the client queue.

`--vrde-property=LogPath=value`

  Specifies the absolute path to the audio log file.

`--vrde-extpack=default | name`

  Specifies the library to use to access the VM remotely. The `default` value uses the RDP code that is part of the &product-name; Extension Pack.

  To use the VRDE module in VNC, specify `VNC`. See .

`--vrde-port=default | port`

  port is the port or port range to which the VRDE server binds. The `default` or `0` value uses port `3389`, which is the standard RDP port.

  You can specify a comma-separated list of ports or port ranges of ports. Use a dash between two port numbers to specify a port range. The VRDE server binds to only one of the available ports from the list. Only one machine can use a given port at a time. For example, the `--vrde-port=5000,5010-5012` option specifies that server can bind to one of following ports: `5000`, `5010`, `5011`, or `5012`.

`--vrde-address=IP-address`

  Specifies the IP address of the host network interface to which the VRDE server binds. If you specify an IP address, the server accepts connections only on the specified host network interface.

  Use this option to specify whether the VRDP server should accept IPv4, IPv6, or both type of connections:

  - Only IPv4: Use the `--vrde-address="0.0.0.0"` option.

  - Only IPv6: Use the `--vrde-address="::"` option.

  - Both IPv6 and IPv4: Use the `--vrde-address=""` option. This is the default value.

`--vrde-auth-type=null | external | guest`

  Specify whether to use authorization and how to perform authorization. See . Valid values are as follows:

  - `null` provides no authentication.

  - `external` provides external authentication through an authentication library.

  - `guest` performs authentication by using guest user accounts. This unsupported method requires that you install the Guest Additions on the VM.

`--vrde-auth-library=default | name`

  Specifies the library to use for RDP authentication. The default library for external authentication is `VBoxAuth`. See .

`--vrde-multi-con=on | off`

  Enables or disables the multiple connections VRDE server feature, if supported. See .

`--vrde-reuse-con=on | off`

  Specifies how the VRDE server behaves when multiple connections are disabled. When the value is `on`, the server permits a new client to connect and drops the existing connection. When the value is `off`, a new connection is not accepted if a client is already connected to the server. This is the default value.

`--vrde-video-channel=on | off`

  Enables video redirection if supported by the VRDE server. See .

`--vrde-video-channel-quality=percent`

  Specifies the image quality for video redirection as a value from 10 to 100 percent. The percentage represents the JPEG compression level where a lower number diminishes quality and provides higher compression. See .

### Teleporting Settings

The following options enable you to configure a machine as a teleporting target. See and the teleporting related entries in .

`--teleporter=on | off`

  Enables or disables the teleporter. When enabled, a machine starts up and waits to receive a teleporting request from the network instead of booting normally.

  Teleporting requests are received on the port and address specified using the following parameters.

`--teleporter-port=port`

  Specifies the port on which the VM listens to receive a teleporting request from another VM. port is any free TCP/IP port number, such as `6000`. You must also specify the `--teleporter` option.

`--teleporter-address=IP-address`

  Specifies the IP address on which the VM listens to receive a teleporting request from another VM. IP-address is any IP address or host name and specifies the TCP/IP socket on which to bind. The default IP address is `0.0.0.0`, which represents any IP address. You must also specify the `--teleporter` option.

`--teleporter-password=password`

  Specifies the password to use for authentication. When specified, the teleporting request only succeeds if the password on the source machine is the same password as the one you specify.

`--teleporter-password-file=filename`

  Specifies a file that contains the password to use for authentication. When specified, the teleporting request only succeeds if the password on the source machine is the same password as the one you specify in the password file. A value of `stdin` reads the password from standard input.

`--cpuid-portability-level=level`

  Restricts the virtual CPU capabilities that &product-name; presents to the guest OS by using portability rules. Higher integer values designate more restrictive behavior. The default level of `0` indicates that all virtualized features supported by the host are made available to the guest. The value `3` suppresses most features. Values of `1` and `2` represent restrictions in between. The behavior may change depending on the product version.

`--cpuid-set=leaf[:subleaf] eax ebx ecx edx`

  Advanced users can use this setting before a teleporting operation (in fact before starting the VM) to restrict the virtual CPU capabilities that &product-name; presents to the guest operating system. This must be run on both the source and the target machines involved in teleporting and will then modify what the guest sees when it executes the CPUID machine instruction. This might help with misbehaving applications that wrongly assume that certain CPU capabilities are present. The meaning of the parameters is hardware dependent. Refer to the AMD or Intel processor documentation.

  The values of leaf, subleaf (optional), eax, ebx, ecx and edx are integers given in hexadecimal format, i.e. using a radix (base) of 16 without requiring any prefix.

`--cpuid-remove=leaf[:subleaf]`

  Removes an adjustment established with `--cpuid-set`.

`--cpuid-remove-all`

  Removes all adjustments established with `--cpuid-set`.

### Debugging Settings

Only use the following options to perform low-level VM debugging. These options are for advanced users only.

`--tracing-enabled=on | off`

  Enables or disables the trace buffer. Note that when specified, the trace buffer consumes some memory and adds overhead.

`--tracing-config=config-string`

  Enables a tracing configuration that defines which group of trace points are enabled.

`--tracing-allow-vm-access=on | off`

  Enables or disables VM access to the trace buffer. The default value is `off`, which disables access.

### USB Card Reader Settings

The following options specify the access to a USB Card Reader by the guest environment. A USB card reader can access data on memory cards, such as CompactFlash (CF), Secure Digital (SD), and MultiMediaCard (MMC).

`--usb-card-reader=on | off`

  Enables or disables the USB card reader interface.

### Autostarting VMs During Host System Boot

The following options enable you to configure the VM autostart feature, which automatically starts the VM at host system boot-up. You must do some host system configuration before you can use this feature. See .

`--autostart-enabled=on | off`

  Enables or disables VM autostart at host system boot-up for the specified users.

`--autostart-delay=seconds`

  Specifies the number of seconds after host system boot-up to autostart the VM.

### Guest Debugging

These options are for configuring the VMM for guest debugging.

`--guest-debug-provider=none | native | gdb | kd`

  Selects the given debug stub provider.

`--guest-debug-io-provider=none | tcp | udp | ipc`

  Selects the given I/O transport backend for the selected provider.

`--guest-debug-address=IP-Address | path`

  Sets the path the debugger is accessible under, depends on the selected I/O transport.

`--guest-debug-port=port`

  Sets the port the debugger is accessible under, depends on the selected I/O transport.

### PCI Passthrough Settings

The following options enable you to configure the PCI passthrough feature, which currently is not available in &product-name;. It is planned to bring this functionality back in the future.

`--pci-attach=host-PCI-address[@guest-PCI-bus-address]`

  Attaches the specified PCI network controller on the host to the guest VM. You can optionally specify the PCI bus on the guest VM on which to attach the controller.

`--pci-detach=host-PCI-address`

  Detaches the specified PCI network controller from the attached PCI bus on the guest VM.

### Testing (ValidationKit / Bootsector)

These options are for configuring the testing functionality of the VMM device and almost exclusively used by the bootsector testcases in the ValidationKit.

`--testing-enabled=on | off`

  Enabled the testing functionality of the VMMDev. See VMMDevTesting.h for details.

`--testing-mmio=on | off`

  Enabled the MMIO region of the VMMDev testing feature.

`--testing-cfg-dwordidx=value`

  This sets one of the 10 dword configuration values. The idx must be in the range 0 through 9. The value is limited to 32 bits (dword).

## Examples

The following command changes the description for the `ol7` VM.

    $ VBoxManage modifyvm ol7 --description "Oracle Linux 7 with UEK4"

The following command enables VirtualBox Remote Display Protocol (VRDP) support for the `ol7` VM.

    $ VBoxManage modifyvm ol7 --vrde on

## See Also

, , ,