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qemu-start(1) manual page


qemu−start − start qemu safely with tap devices


qemu−start [OPTIONS] -- QEMUOPTS...


This manual page documents the qemu-start command.

qemu-start is a small program that helps you start qemu in a safe and useful way. It presumes all qemu instances will run under the same user-id (qemu). A group emulator is created; only members of this group are allowed to start qemu. Qemu is started with one ethernet interface, which is bound through a tap device. Xauthority data is automatically transferred if the DISPLAY variable is set.


The parameter --tapnr TAPDEVNR is the number of the tap−device. Use 0 for tap0, etc. See below how you safely can define tap devices.

The parameter --vlan VLAN is the VLAN you want to add this adapter to. Usually, using 0 will do.

The parameter --nic-model NICMODEL is the model type of the emulated nic presented to the guest os. Use qemu -net nic,model=? for information on allowed values for this parameter

The parameter --macaddr MACADDRESS sets the MAC address for the emulated nic presented to guest os.

The parameter --system SYSTEM is the system you want to emulate. Leave out if you want to use your current architecture; in this case, /usr/bin/qemu will be called. If you want to simulate some other type of system, specify it here; in that case, /usr/bin/qemu-system-SYSTEM will be called.

The parameter --window-left X sets the left-most column of the window (in pixels) to X.

The parameter --window-top Y sets the top-most row of the window (in pixels) to Y.

All options and parameters after -- are fed to qemu.


You must create a tap device for use by qemu. The nicest way of doing this is combining it with a bridge. This section describes how you can do this.

Make sure you have the packages bridge-utils and uml-utilities installed.

Edit /etc/network/interfaces. Find the section where your current ethernet interface is described; we will assume here it is eth0. Change its name to br0 and add the following line to the stanza:

bridge_ports eth0 tap0

You can add more tap devices later if you want. Now add a stanza for the new tap interface:

auto tap0
iface tap0 inet manual
tunctl_user qemu

Finally, restart your netwerk by issuing a command /etc/init.d/networking restart




qemu-start was written by Frodo Looijaard <frodo@frodo.looijaard.name>.

This manual page was written by Frodo Looijaard <frodo@frodo.looijaard.name>

General_article | by Dr. Radut