openstack-manuals/doc/image-guide/source/virt-install.rst

Use virt-install and connect by using a local VNC client

If you do not wish to use virt-manager (for example, you do not want to install the dependencies on your server, you do not have an X server running locally, the X11 forwarding over SSH is not working), you can use the virt-install tool to boot the virtual machine through libvirt and connect to the graphical console from a VNC client installed on your local machine.

Because VNC is a standard protocol, there are multiple clients available that implement the VNC spec, including TigerVNC <http://sourceforge.net/apps/mediawiki/tigervnc/ index.php?title=Welcome_to_TigerVNC> (multiple platforms), TightVNC (multiple platforms), RealVNC (multiple platforms), Chicken (Mac OS X), Krde (KDE), Vinagre (GNOME).

The following example shows how to use the qemu-img command to create an empty image file, and virt-install command to start up a virtual machine using that image file. As root:

# qemu-img create -f qcow2 /tmp/centos.qcow2 10G
# virt-install --virt-type kvm --name centos --ram 1024 \
  --disk /tmp/centos.qcow2,format=qcow2 \
  --network network=default \
  --graphics vnc,listen=0.0.0.0 --noautoconsole \
  --os-type=linux --os-variant=centos7.0 \
  --location=/data/isos/CentOS-7-x86_64-NetInstall-1611.iso

Starting install...
Creating domain...                     |    0 B     00:00
Domain installation still in progress. You can reconnect to
the console to complete the installation process.

The KVM hypervisor starts the virtual machine with the libvirt name, centos, with 1024 MB of RAM. The virtual machine also has a virtual CD-ROM drive associated with the /data/isos/CentOS-7-x86_64-NetInstall-1611.iso file and a local 10 GB hard disk in qcow2 format that is stored in the host at /tmp/centos.qcow2. It configures networking to use libvirt default network. There is a VNC server that is listening on all interfaces, and libvirt will not attempt to launch a VNC client automatically nor try to display the text console (--no-autoconsole). Finally, libvirt will attempt to optimize the configuration for a Linux guest running a CentOS 7 distribution.

Note

When using the libvirt default network, libvirt will connect the virtual machine's interface to a bridge called virbr0. There is a dnsmasq process managed by libvirt that will hand out an IP address on the 192.168.122.0/24 subnet, and libvirt has iptables rules for doing NAT for IP addresses on this subnet.

Run the osinfo-query os command to see a range of allowed --os-variant options.

Use the virsh vncdisplay vm-name command to get the VNC port number.

# virsh vncdisplay centos
:1

In the example above, the guest centos uses VNC display :1, which corresponds to TCP port 5901. You should be able to connect a VNC client running on your local machine to display :1 on the remote machine and step through the installation process.