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Overview

When users are off-site or have slow internet connections, displaying graphics can be cumbersome.  PCDS has explored two solutions for this problem:

  1. The first ("NX technology") gives the user a special remote desktop that is specifically designed to improve the performance of X11 graphics over slow connection speeds (compared to ssh).  
  2. The second ("Virtual Box") allows the user to directly install the psana analysis environment on their Windows, Linux or Mac machine, so that LCLS data analysis (including graphics) can be done with no network connection (click here for information on the virtual box approach).

This page is about the usage of NoMachine for providing NX technology to users involved in LCLS experiments or operations.

NX Technology

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/NoMachine NX is supported on Windows, MAC and Linux computers. 

Minimum System Requirements

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Note: MAC Clients must install XCode and XQuartz.You can download XQuartz from https://www.xquartz.org.

Installation

You can download the latest version of the enterprise client from https://www.NoMachinenomachine.com/download-enterprise#NoMachine-Enterprise-Client. Ubuntu/Mint users should download the Debian version of the NoMachine client.

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You will be prompted to setup a login profile when launching the NoMachine for the first time. Select the following options:


Protocol: SSH
Host: psnxserv.slac.stanford.edu,  Port: 22
Authentication: Use the System Login (not the "NoMachine Login"). Do not select 'Use an alternate server key'. Use Password authentication
Proxy: Don't use a proxy
Save as: Choose a name such as PSNXSERV. You could select 'Create a link on the desktop'
Select Done to finish the setup

You can hit Connect to start the connection.

You may be asked to verify host authenticity. Hit Continue.

You will be asked to type Username and Password. Use your SLAC UNIX account and password and hit OK.

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Please contact pcds-it-l@slac.stanford.edu if you need more information or additional assistance with NoMachine.

Middle mouse button emulation for Mac users

MacOs users may wish to have middle mouse button functionality enabled in their NoMachine sessions. 

Here are the required settings within the XQuartz Preferences section (access via XQuartz→Preferences):

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Use in EPICS EDM Displays

One of the common uses of this feature is to display the EPICS process variable (PV) names associated with widgets on EDM-based operator screens. Once these preferences are set then Option-Click displays the PV name upon release of the click (it is not displayed when still depressed) - and puts it into the cut-and-paste buffer.


Troubleshooting

bashrc

Avoid sourcing the psconda environment when accessing the NoMachine servers.  To add the conda environment to your profile edit $HOME/.bashrc with the following content:

  • Set an alias to source it manually:
Code Block
title.bashrc
 alias psconda='source /reg/g/psdm/etc/psconda.sh' 
  • Only source the environment on the ana nodes :
Code Block
title.bashrc
export MN=$(uname -n)
if [[ "$MN" =~ ^psana ]]; then
    source /reg/g/psdm/etc/psconda.sh
fi

Connection Issues

If you are not able to connect to NoMachine, check the followings:

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Show all running user processes: 
Code Block
languagebash
ps -f -u $USERNAME

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