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Remote Desktop Access	NX, nomachine, remote desktop access, login node, merlin-l-001, merlin-l-002, merlin-nx-01, merlin-nx-02, merlin-nx, rem-acc, vpn	07 September 2022	merlin6_sidebar	/merlin6/nomachine.html

Users can login in Merlin through a Linux Remote Desktop Session. NoMachine is a desktop virtualization tool. It is similar to VNC, Remote Desktop, etc. It uses the NX protocol to enable a graphical login to remote servers.

Installation

NoMachine is available for PSI Windows computers in the Software Kiosk under the name NX Client. Please use the latest version (at least 6.0). For MacOS and Linux, the NoMachine client can be downloaded from https://www.nomachine.com/.

Accessing Merlin6 NoMachine from PSI

The Merlin6 NoMachine service is hosted in the following machine:

• merlin-nx.psi.ch

This is the front-end (hence, the door) to the NoMachine back-end nodes, which contain the NoMachine desktop service. The back-end nodes are the following:

• merlin-l-001.psi.ch
• merlin-l-002.psi.ch

Any access to the login node desktops must be done through merlin-nx.psi.ch (or from rem-acc.psi.ch -> merlin-nx.psi.ch when connecting from outside PSI).

The front-end service running on merlin-nx.psi.ch will load balance the sessions and login to any of the available nodes in the back-end.

Only 1 session per back-end is possible.

Below are explained all the steps necessary for configuring the access to the NoMachine service running on a login node.

Creating a Merlin6 NoMachine connection

Adding a new connection to the front-end

Click the Add button to create a new connection to the merlin-nx.psi.ch front-end, and fill up the following fields:

• Name: Specify a custom name for the connection. Examples: merlin-nx, merlin-nx.psi.ch, Merlin Desktop
• Host: Specify the hostname of the front-end service: merlin-nx.psi.ch
• Protocol: specify the protocol that will be used for the connection. Recommended protocol: NX
• Port: Specify the listening port of the front-end. It must be 4000.

![Create New NoMachine Connection]({{ "/images/NoMachine/screen_nx_connect.png" }})

Configuring NoMachine Authentication Method

Depending on the client version, it may ask for different authentication options. If it's required, choose your authentication method and Continue (Password or Kerberos are the recommended ones).

You will be requested for the crendentials (username / password). Do not add PSICH\ as a prefix for the username.

Opening NoMachine desktop sessions

By default, when connecting to the merlin-nx.psi.ch front-end it will automatically open a new session if none exists.

If there are existing sessions, instead of opening a new desktop session, users can reconnect to an existing one by clicking to the proper icon (see image below).

![Open an existing Session]({{ "/images/NoMachine/screen_nx_existingsession.png" }})

Users can also create a second desktop session by selecting the New Desktop button (red rectangle in the below image). This will create a second session on the second login node, as long as this node is up and running.

![Open a New Desktop]({{ "/images/NoMachine/screen_nx_newsession.png" }})

NoMachine LightDM Session Example

An example of the NoMachine session, which is based on LightDM X Windows:

![NoMachine Session: LightDM Desktop]({{ "/images/NoMachine/screen_nx11.png" }})

Accessing Merlin6 NoMachine from outside PSI

No VPN access

Access to the Merlin6 NoMachine service is possible without VPN through 'rem-acc.psi.ch'. Please follow the steps described in PSI Remote Interactive Access for remote access to the Merlin6 NoMachine services. Once logged in 'rem-acc.psi.ch', you must then login to the merlin-nx.psi.ch front-end . services.

VPN access

Remote access is also possible through VPN, however, you must not use 'rem-acc.psi.ch', and you have to connect directly to the Merlin6 NoMachine merlin-nx.psi.ch front-end as if you were inside PSI. For VPN access, you should request it to the IT department by opening a PSI Service Now ticket: VPN Access (PSI employees).

Advanced Display Settings

Nomachine Display Settings can be accessed and changed either when creating a new session or by clicking the very top right corner of a running session.

Prevent Rescaling

These settings prevent "bluriness" at the cost of some performance! (You might want to choose depending on performance)

• Display > Resize remote display (forces 1:1 pixel sizes)
• Display > Change settings > Quality: Choose Medium-Best Quality
• Display > Change settings > Modify advanced settings
  • Check: Disable network-adaptive display quality (diables lossy compression)
  • Check: Disable client side image post-processing