Ubuntu Server installs virtual machines

The virtual machines on the server are KVM.
To install a virtual system, you first need to obtain a mirror image of the system. Mirrors can be downloaded in a number of places, giving a few common mirror addresses:

Address
http://mirrors.aliyun.com/	Aliyun Mirroring
http://mirror.bit.edu.cn/	Beijing Polytechnic University Open source software mirroring service
http://mirrors.163.com/	NetEase Open Source Mirror station
http://mirrors.xmu.edu.cn/	Information and Network Center of Xiamen University Open source software mirroring service

When I downloaded the Ubuntu server, I tested every source, and the Aliyun mirror was the fastest.
How to install KVM refer to this blog: http://www.server110.com/kvm/201403/8321.html. The KVM on the server was already installed by the previous seniors, so I didn't install it myself.
The next step is to divide the virtual disk. When the virtual disk is installed, the captured mirror is mounted to the disk.
There is a problem when installing the system, the virtual machine prompts require a graphical interface. The previous steps are connected to the server with SSH to complete, the next biggest problem is how to Ann graphics interface.
To install the graphical interface command: Apt-get install Ubuntu-desktop
After the installation has always wanted to use the Xmananger on their own computer to connect to the desktop up, but has been an error. Forced to go to the computer room to take the monitor directly to the server.
When you open the graphical interface, there is a hole, in the command line after the input startx, there will be a graphical interface. But this interface is very difficult to see, there is no menu, can not control the window. You should use LIGHTDM start to get into the normal Ubuntu desktop.
Download Virt-manager, this is a graphical management of KVM software. Use this to create a new virtual machine, and then copy several. Network mode is the choice of NAT, this mode can only connect between the intranet, the virtual machine can access the extranet, but from the extranet is unable to connect to the virtual machine via SSH. If you choose a NAT,IP address or do not need to assign yourself, it is ready.