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VMCTL(8) System Manager's Manual VMCTL(8)

vmctlcontrol the virtual machine daemon

vmctl command [arg ...]

The vmctl utility is used to control the virtual machine monitor (VMM) subsystem. A VMM manages virtual machines (VMs) on a host. The VMM subsystem is responsible for creating, destroying, and executing VMs.

Within the commands, the size argument can be specified with a human-readable scale, using the format described in scan_scaled(3). The id argument can be either a numeric, non-zero identifier or alternatively the name of a virtual machine.

The commands are as follows:

Using cu(1) connect to the console of the VM with the specified id.
path -s size
Creates a VM disk image file with the specified path and size, rounded to megabytes.
Load additional configuration from the specified file.
Disable verbose debug logging.
Enable verbose debug logging.
Remove all stopped VMs and reload the configuration from the default configuration file.
Reset the running state.
Reset the configured switches.
Reset and terminate all VMs.
name [-b path] [-c] [-d path] [-i count] [-m size] [-n switch]
Starts a VM defined by the specified name and parameters:
Boot the VM with the specified kernel or BIOS image. If not specified, the default is to boot using the BIOS image in /etc/firmware/vmm-bios.
Automatically connect to the VM console.
Disk image file (may be specified multiple times to add multiple disk images).
Number of network interfaces to add to the VM.
Memory size of the VM, rounded to megabytes. The default is 512M.
Add a network interface that is attached to the specified virtual switch. See SWITCH CONFIGURATION in vm.conf(5) for more information.
Lists VMs running on the host, optionally listing just the selected VM id.
Stops (terminates) a VM defined by the specified VM id. A graceful shutdown will be attempted if the VM supports the vmmci(4) device. Once stopped, if the VM was not defined in a configuration file, then it is removed.

If the -i option is specified during VM startup, a corresponding number of host-side tap(4) interfaces will be allocated and mapped to the vio(4) interfaces inside the guest VM. This tap/vio interface mapping allows guest network traffic to be manipulated by the host. Any valid host-side interface configuration may be performed on these tap interfaces, such as bridging (via bridge(4)), or using pf(4) nat-to rules to create private or host-side NATed networks, as desired.

Default configuration file.
UNIX-domain socket used for communication with vmd(8).

The vmctl utility exits 0 on success, and >0 if an error occurs. vmctl may fail due to one of the following reasons:

Create a 4.5 Gigabyte disk image, disk.img:

$ vmctl create disk.img -s 4.5G

Create a new VM with 1GB memory, one network interface, one disk image ('disk.img') and boot from kernel '/bsd':

# vmctl start "myvm" -m 1G -i 1 -d disk.img

vmd(8) will create a new tap(4) network interface on the host side and set the description to indicate the VM by ID, interface number, and name:

# ifconfig tap0
	lladdr fe:e1:ba:d8:50:d1
	description: vm1-if0-myvm
	index 15 priority 0 llprio 3
	groups: tap
	status: active

Terminate VM number 1:

# vmctl stop 1

bridge(4), pf(4), tap(4), vio(4), vmm(4), vm.conf(5), rc.conf(8), vmd(8)

The vmctl command first appeared in OpenBSD 5.9.

Mike Larkin <> and Reyk Floeter <>.

March 25, 2017 OpenBSD-6.1