qubes-doc/en/reference/dom0-tools/qvm-prefs.md

---
layout: doc
title: qvm-prefs
permalink: /en/doc/dom0-tools/qvm-prefs/
redirect_from:
- /doc/Dom0Tools/QvmPrefs/
- /wiki/Dom0Tools/QvmPrefs/
---

qvm-prefs
=========

NAME
----

qvm-prefs - list/set various per-VM properties

Date  
2012-04-11

SYNOPSIS
--------

qvm-prefs -l [options] \<vm-name\>
qvm-prefs -g [options] \<vm-name\> \<property\>
qvm-prefs -s [options] \<vm-name\> \<property\> [...]

OPTIONS
-------

-h, --help  
Show this help message and exit

-l, --list  
List properties of a specified VM

-g, --get  
Get a single property of a specified VM

-s, --set  
Set properties of a specified VM

PROPERTIES
----------

include\_in\_backups  
Accepted values: `True`, `False`

Control whenever this VM will be included in backups by default (for now works only in qubes-manager). You can always manually select or deselect any VM for backup.

pcidevs  
PCI devices assigned to the VM. Should be edited using qvm-pci tool.

pci\_strictreset  
Accepted values: `True`, `False`

Control whether prevent assigning to VM a device which does not support any reset method. Generally such devices should not be assigned to any VM, because there will be no way to reset device state after VM shutdown, so the device could attack next VM to which it will be assigned. But in some cases it could make sense - for example when the VM to which it is assigned is trusted one, or is running all the time.

label  
Accepted values: `red`, `orange`, `yellow`, `green`, `gray`, `blue`, `purple`, `black`

Color of VM label (icon, appmenus, windows border). If VM is running, change will be applied at first VM restart.

netvm  
Accepted values: netvm name, `default`, `none`

To which NetVM connect. Setting to `default` will follow system-global default NetVM (managed by qubes-prefs). Setting to `none` will disable networking in this VM.

dispvm\_netvm  
Accepted values: netvm name, `default`, `none`

Which NetVM should be used for Disposable VMs started by this one. `default` is to use the same NetVM as the VM itself.

maxmem  
Accepted values: memory size in MB

Maximum memory size available for this VM. Dynamic memory management (aka qmemman) will not be able to balloon over this limit. For VMs with qmemman disabled, this will be overridden by *memory* property (at VM startup).

memory  
Accepted values: memory size in MB

Initial memory size for VM. This should be large enough to allow VM startup - before qmemman starts managing memory for this VM. For VM with qmemman disabled, this is static memory size.

kernel  
Accepted values: kernel version, `default`, `none`

Kernel version to use (only for PV VMs). Available kernel versions will be listed when no value given (there are in /var/lib/qubes/vm-kernels). Setting to `default` will follow system-global default kernel (managed via qubes-prefs). Setting to `none` will use "kernels" subdir in VM directory - this allows having VM-specific kernel; also this the only case when /lib/modules is writable from within VM.

template  
Accepted values: TemplateVM name

TemplateVM on which VM base. It can be changed only when VM isn't running.

vcpus  
Accepted values: no of CPUs

Number of CPU (cores) available to VM. Some VM types (eg DispVM) will not work properly with more than one CPU.

kernelopts  
Accepted values: string, `default`

VM kernel parameters (available only for PV VMs). This can be used to workaround some hardware specific problems (eg for NetVM). Setting to `default` will use some reasonable defaults (currently different for VMs with PCI devices and without). For VM without PCI devices `default` option means inherit this value from the VM template (if any). Some helpful options (for debugging purposes): `earlyprintk=xen`, `init=/bin/bash`

name  
Accepted values: alphanumerical name

Name of the VM. Can be only changed when VM isn't running.

drive  
Accepted values: [hd:|cdrom:][backend-vm:]path

Additional drive for the VM (available only for HVMs). This can be used to attach installation image. `path` can be file or physical device (eg. /dev/sr0). The same syntax can be used in qvm-start --drive - to attach drive only temporarily.

mac  
Accepted values: MAC address, `auto`

Can be used to force specific of virtual ethernet card in the VM. Setting to `auto` will use automatic-generated MAC - based on VM id. Especially useful when some licencing depending on static MAC address. For template-based HVM `auto` mode means to clone template MAC.

default\_user  
Accepted values: username

Default user used by qvm-run. Note that it make sense only on non-standard template, as the standard one always have "user" account.

debug  
Accepted values: `on`, `off`

Enables debug mode for VM. This can be used to turn on/off verbose logging in many qubes components at once (gui virtualization, VM kernel, some other services). For template-based HVM, enabling debug mode also disables automatic reset root.img (actually volatile.img) before each VM startup, so changes made to root filesystem stays intact. To force reset root.img when debug mode enabled, either change something in the template (simple start+stop will do, even touch its root.img is enough), or remove VM's volatile.img (check the path with qvm-prefs).

qrexec\_installed  
Accepted values: `True`, `False`

This HVM have qrexec agent installed. When VM have qrexec agent installed, one can use qvm-run to start VM process, VM will benefit from Qubes RPC services (like file copy, or inter-vm clipboard). This option will be automatically turned on during Qubes Windows Tools installation, but if you install qrexec agent in some other OS, you need to turn this option on manually.

guiagent\_installed  
Accepted values: `True`, `False`

This HVM have gui agent installed. This option disables full screen GUI virtualization and enables per-window seemless GUI mode. This option will be automatically turned on during Qubes Windows Tools installation, but if you install qubes gui agent in some other OS, you need to turn this option on manually. You can turn this option off to troubleshoot some early HVM OS boot problems (enter safe mode etc), but the option will be automatically enabled at first VM normal startup (and will take effect from the next startup).

*Notice:* when Windows GUI agent is installed in the VM, SVGA device (used to full screen video) is disabled, so even if you disable this option, you will not get functional full desktop access (on normal VM startup). Use some other means for that (VNC, RDP or so).

autostart  
Accepted values: `True`, `False`

Start the VM during system startup. The default netvm is autostarted regardless of this setting.

timezone  
Accepted values: `localtime`, time offset in seconds

Set emulated HVM clock timezone. Use `localtime` (the default) to use the same time as dom0 have. Note that HVM will get only clock value, not the timezone itself, so if you use `localtime` setting, OS inside of HVM should also be configured to treat hardware clock as local time (and have proper timezone set).

AUTHORS
-------

Joanna Rutkowska \<joanna at invisiblethingslab dot com\>
Rafal Wojtczuk \<rafal at invisiblethingslab dot com\>
Marek Marczykowski \<marmarek at invisiblethingslab dot com\>