--- title: Remote Desktop Access keywords: NX, nomachine, remote desktop access, login node, login001, login002, merlin7-nx-01, merlin7-nx-02, merlin7-nx, rem-acc, VPN, browser access last_updated: 07 August 2024 sidebar: merlin7_sidebar permalink: /merlin7/nomachine.html --- Users can log in to Merlin through a Linux Remote Desktop Session. NoMachine is a desktop virtualization tool similar to VNC, Remote Desktop, etc. It uses the NX protocol to enable a graphical login to remote servers. ## New Feature: Browser-Based Access We have now enabled browser-based access to Merlin7. This allows users to connect to the NoMachine service directly through a web browser, removing the need to install a client application. This is accessible via the following URL: - **Browser Endpoint**: [https://merlin7-nx.psi.ch:4443](https://merlin7-nx.psi.ch:4443) ### How to Connect via Browser 1. Open your web browser and navigate to [https://merlin7-nx.psi.ch:4443](https://merlin7-nx.psi.ch:4443). 2. Enter your credentials when prompted. **Do not add `PSICH\`** as a prefix for the username. 3. Follow the on-screen instructions to launch a new session or reconnect to an existing one. ## Installation For traditional access, NoMachine is available for PSI Windows computers in the Software Kiosk under the name **NX Client**. Please use the latest version (at least 8.1.3). For macOS and Linux, the NoMachine client can be downloaded from [https://www.nomachine.com/](https://www.nomachine.com/). ## Accessing Merlin7 NoMachine from PSI The Merlin7 NoMachine service is hosted on the following machine: - **`merlin7-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: - `login001.merlin7.psi.ch` - `login002.merlin7.psi.ch` Any access to the login node desktops must be done through **`merlin7-nx.psi.ch`**. The **front-end** service running on **`merlin7-nx.psi.ch`** will load-balance the sessions and log in to any available nodes in the **back-end**. **Only one session per back-end** is possible. Below are all the steps necessary for configuring access to the NoMachine service running on a login node. ### Creating a Merlin7 NoMachine Connection #### Adding a New Connection to the Front-End Click the **Add** button to create a new connection to the **`merlin7-nx.psi.ch` front-end**, and fill up the following fields: - **Name**: Specify a custom name for the connection. Examples: `merlin7-nx`, `merlin7-nx.psi.ch`, `Merlin Desktop` - **Host**: Specify the hostname of the **front-end** service: **`merlin7-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`** for the **`NX`** protocol. ![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 required, choose your authentication method and **Continue** (**Password** or *Kerberos* are recommended). You will be requested for the credentials (username/password). **Do not add `PSICH\`** as a prefix for the username. ### Opening NoMachine Desktop Sessions By default, when connecting to the **`merlin7-nx.psi.ch` front-end**, a new session automatically opens if none exists. If there are existing sessions, users can reconnect to an existing one instead of opening a new desktop session by clicking the appropriate 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 image below). This will create a second session on the second login node as long as it 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](https://github.com/canonical/lightdm) X Windows: ![NoMachine Session: LightDM Desktop]({{ "/images/NoMachine/screen_nx11.png" }}) ## Accessing Merlin7 NoMachine from Outside PSI ### No Direct Access Without VPN During the pre-production phase, direct access to the NoMachine service from outside the organization is not supported. To access the service, you must first connect to PSI's VPN. The external **rem-acc.psi.ch** service does not yet allow direct access to the new cluster without a VPN connection. ### VPN Access Remote access is possible through VPN; however, you **must not use 'rem-acc.psi.ch'**, and you have to connect directly to the Merlin7 NoMachine **`merlin7-nx.psi.ch` front-end** as if you were inside PSI. For VPN access, you should request it from the IT department by opening a PSI Service Now ticket: [VPN Access (PSI employees)](https://psi.service-now.com/psisp?id=psi_new_sc_cat_item&sys_id=beccc01b6f44a200d02a82eeae3ee440). ## Advanced Display Settings **NoMachine Display Settings** can be accessed and changed when creating a new session or by clicking the top right corner of a running session. ### Prevent Rescaling These settings prevent "blurriness" 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 (turns off lossy compression) - Check: Disable client-side image post-processing