Lab FAQ: Access to virtual machine / Virtual lab

There are two ways to enter our virtual machine, Depending on the use that is going to give her. If you are a student/teacher access to the console and/or reinstallation of the virtual machine itself, you have access to the virtualization system, otherwise, you only have access via SSH and open ports previously requested depending on the type of laboratory practice. Students/teachers who have access to the virtualization system, también tienen a su vez acceso por SSH/Puertos específicos a su máquina virtual.

 

Access to system virtualization:

https://matrix.inf.uva.es

Nos aparecerá una ventana como la siguiente, which will have to fill with our username/password details. Tanto alumnos como los profesores de la Escuela de Ingeniería Informática, deberán elegir en “Domain” the LAB option. Teachers who do not have account in the laboratories of the school, they must choose the option “PVE”. Once this step, We will already be within the virtualization system.

Once inside, We can see the availability of the cluster, and we will have to look between our different servers / machine. Another option, is from the list on the right, Double click to the virtual machine and now go into your options.

Once selected the virtual machine, We can start it, stop it, turn it off, reseted, Open the console and enter an ISO image on CD-ROM drive virtual.

In the top right of the page, We have the following options:

  • Home: Starts the virtual machine (If not it is already).
  • Orderly closure: It gives us several options. Locking computer, Turn off and Reset. Por defecto la acción de ese boton es apagar la máquina ordenadamente y así lo hará si la máquina tiene soporte ACPI correctamente instalado.
  • Migration: This option only is available for system administrators.
  • Console: Opens a new window with the virtual machine console KVM, from which you can perform an installation or any needs requiring a presence in front of the machine.

 

SSH access to the virtual machine:

All virtual machines in the laboratories have by default the SSH port open, following a pattern that is explained below. Es posible que las máquinas tengan mas puertos abiertos, but in that case, the teacher in charge of the virtual laboratory, indicará a los alumnos dichos puertos.

El puerto para acceder a nuestra máquina virtual se forma de la siguiente forma:

For example, tenemos adjudicada la máquina con ID 4501, the port would be:

virtual.lab.inf.UVA.es –> 4501L
virtual.lab.inf.UVA.es –> 45011

Where L is a number of 1 a. 9 services which may be of each virtual machine. By default, L = 1 is the SSH port.

 

Virtual laboratories network topology:

Although each student is assigned a hostname of different machine to gain access to your virtual machine, the truth is that in reality all the virtual machines from the Internet respond to the same IP (virtual.lab.inf.UVA.es), It is a server that does NAT to reach the VPN virtual machines. Esto no es necesariamente así desde dentro de la máquina virtual, that being in the private network, they need to necessarily have a hostname and IP address different. In this way, we gain in security, evitando desperdiciar IPs públicas y que el alumno recuerde el ID de su máquina virtual para saber a que puerto SSH tiene que acceder, según la explicación anterior.

A graph of the network topology scheme would be as follows: