Question: How to create and use a virtual server?
Author: J. Tam
Date: 2018-06-28
Introduction
A virtual server can be created for a department member's use, and is
useful for computational needs that require more resources than the member
has, or requires a different operating system than they have access to.
It is also useful for developing applications in conjunction with other
department members, or requires stable network access.
Only department faculty members can request the creation of a virtual
server. Students or visitors who need a virtual server should ask their
supervisor to contact the IT staff to create one on their behalf.
Typically, virtual servers will be installed with a version of Unix,
such as RedHat or Ubuntu. Other types of OS's can be created but they
must be by special requests. The rest of this FAQ assumes that a virtual
server with Unix has been installed.
Access to virtual server
Unix virtual servers are typically accessed via ssh command line.
This allows users to securely connect to their virtual server from remote
networks to issue commands to the virtual server.
Many OSs, including MacOSX, *nix derivatives (e.g. RedHat, Ubuntu, BSD,
etc.) have ssh pre-installed, so no additional software is required.
Running the ssh client typically starts by opening up a terminal
application, and typing
ssh user@vserver.math.ubc.ca
where user is the MathNet username, and vserver
is the name of the virtual server assigned to the user.
Windows users can download third-party ssh client software. One popular
example of a ssh Windows client is
PuTTY [https://www.putty.org]
Displaying graphical output from a virtual server
For some uses, command line version is sufficient, but if the use
of an applications that displays graphical output (e.g. Maple, Matlab,
desktop GUI, etc.) is required, X-Windows will need to be installed on
the laptop or workstations the user is connecting from. This allows
graphics output to be display on the local monitor.
The procedure to install X-Windows differs depending on the system
it will be installed on:
- Unix systems: most have X-Windows pre-installed,
so additional software won't be needed. If the system does not
have X-Windows, the user can contact the IT staff for help.
- MacOSX: an X-Windows system can be downloaded from
XQuartz [https://www.xquartz.org]
- Windows: an X-Windows system can be downloaded from
VcXsrv [https://sourceforge.net/projects/vcxsrv/]
When starting a ssh session, ssh must be informed that X-Windows is in
use: it will allow X-Windows graphical data to be tunnelled back to the
local display. For sessions initiated by command-line ssh, an extra
-X argument tells ssh to enable X-Windows forwarding e.g.
ssh -X user@vserver.math.ubc.ca
For GUI clients (like PuTTY), X-Windows forwarding can be enabled
in the settings menu.
To be written
These are topics that some users have asked about, but have not been
written up yet. Please contact the IT staff for more information.
- Virtual desktop: x2go
- Passwords
- Shells
- File usage, backup
- Firewall policies?
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