Rewrite NoMachine docs

pages/merlin7/02-How-To-Use-Merlin/nomachine.md

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 ---
-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
+title: Remote Desktop Access to Merlin7
+keywords: NX, NoMachine, remote desktop access, login node, login001, login002, merlin7-nx-01, merlin7-nx, nx.psi.ch, 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.
+## Overview
 
-## New Feature: Browser-Based Access
+Merlin7 NoMachine provides users with remote desktop access to the Merlin7 computing environment. This service enables users to connect to their computing resources from any location, whether they are inside the PSI network or accessing from outside via secure methods.
 
-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:
+## Accessing Merlin7 NoMachine
 
-- **Browser Endpoint**: [https://merlin7-nx.psi.ch:4443](https://merlin7-nx.psi.ch:4443)
+### From Inside PSI
 
-### How to Connect via Browser
+If you are inside the PSI network, you can directly connect to the Merlin7 NoMachine service without the need to go through another service.
 
-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.
+1. **Ensure Network Connectivity**: Make sure you are connected to the PSI internal network.
+2. **Choose Your Access Method**: You can access Merlin7 using either a web browser or the NoMachine client.
 
-## Installation
+#### Method 1: Using a Web Browser
 
-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/).
+Open your web browser and navigate to [https://merlin7-nx.psi.ch:4443](https://merlin7-nx.psi.ch:4443).
 
-## Accessing Merlin7 NoMachine from PSI
+#### Method 2: Using the NoMachine Client
 
-The Merlin7 NoMachine service is hosted on the following machine:
+Settings for the NoMachine client:
 
-- **`merlin7-nx.psi.ch`**
+- **Host**: `merlin7-nx.psi.ch`
+- **Port**: `4000`
+- **Protocol**: `NX`
+- **Authentication**: `Use password authentication`
 
-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:
+### From Outside PSI
 
-- `login001.merlin7.psi.ch`
-- `login002.merlin7.psi.ch`
+Users outside the PSI network have two options for accessing the Merlin7 NoMachine service: through `nx.psi.ch` or via a VPN connection.
 
-Any access to the login node desktops must be done through **`merlin7-nx.psi.ch`**.
+#### Option 1: Via `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**.
+Documentation about the `nx.psi.ch` service can be found [here](https://www.psi.ch/en/photon-science-data-services/remote-desktop-nomachine).
 
-**Only one session per back-end** is possible.
+##### Using a Web Browser
 
-Below are all the steps necessary for configuring access to the NoMachine service running on a login node.
+Open your web browser and navigate to [https://nx.psi.ch](https://nx.psi.ch).
 
-### Creating a Merlin7 NoMachine Connection
+##### Using the NoMachine Client
 
-#### Adding a New Connection to the Front-End
+Settings for the NoMachine client:
 
-Click the **Add** button to create a new connection to the **`merlin7-nx.psi.ch` front-end**, and fill up the following fields:
+- **Host**: `nx.psi.ch`
+- **Port**: `4000`
+- **Protocol**: `NX`
+- **Authentication**: `Use password authentication`
 
-- **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.
+#### Option 2: Via VPN
 
-![Create New NoMachine Connection]({{ "/images/NoMachine/screen_nx_connect.png" }})
+Alternatively, you can use a VPN connection to access Merlin7 as if you were inside the PSI network.
 
-#### Configuring NoMachine Authentication Method
+1. **Request VPN Access**: Contact the IT department to request VPN access if you do not already have it. Submit a request through the PSI Service Now ticketing system: [VPN Access (PSI employees)](https://psi.service-now.com/psisp?id=psi_new_sc_cat_item&sys_id=beccc01b6f44a200d02a82eeae3ee440).
+2. **Connect to the VPN**: Once access is granted, connect to the PSI VPN using your credentials.
+3. **Access Merlin7 NoMachine**: Once connected to the VPN, you can access Merlin7 using either a web browser or the NoMachine client as if you were inside the PSI network.
 
-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).
+## The NoMachine Client
 
-You will be requested for the credentials (username/password). **Do not add `PSICH\`** as a prefix for the username.
+### Installation
+
+#### Windows
+
+The NoMachine client is available for PSI Windows computers in the Software Kiosk under the name **NX Client**.
+
+#### macOS and Linux
+
+The NoMachine client can be downloaded from [NoMachine's download page](https://downloads.nomachine.com).
+
+### Connection Configuration
+
+1. **Launch NoMachine Client**: Open the NoMachine client on your computer.
+2. **Create a New Connection**: Click the **Add** button to create a new connection.
+    - On the **Address** tab configure:
+      - **Name**: Enter a name for your connection. This can be anything.
+      - **Host**: Enter the appropriate hostname (e.g. `merlin7-nx.psi.ch`).
+      - **Port**: Enter `4000`.
+      - **Protocol**: Select `NX`.
+
+    ![Create New NoMachine Connection]({{ "/images/NoMachine/screen_nx_address.png" }})
+
+    - On the **Configuration** tab ensure:
+      - **Authentication**: Select `Use password authentication`.
+
+    ![Create New NoMachine Connection]({{ "/images/NoMachine/screen_nx_configuration.png" }})
+
+    - Click the **Add** button to finish creating the new connection.
+
+## Authenticating
+
+When prompted, use your PSI credentials to authenticate.
+
+![Create New NoMachine Connection]({{ "/images/NoMachine/screen_nx_auth.png" }})
+
+## Managing Sessions
+
+The Merlin7 NoMachine service is managed through a front-end server and back-end nodes, facilitating balanced and efficient access to remote desktop sessions.
+
+### Architecture Overview
+
+- **Front-End Server**: `merlin7-nx.psi.ch`
+  - Serves as the entry point for users connecting to the NoMachine service.
+  - Handles load-balancing and directs users to available back-end nodes.
+
+- **Back-End Nodes**:
+  - `login001.merlin7.psi.ch`
+  - `login002.merlin7.psi.ch`
+  - These nodes host the NoMachine desktop service and manage the individual desktop sessions.
+
+Access to the login node desktops must be initiated through the `merlin7-nx.psi.ch` front-end. The front-end service will distribute sessions across available nodes in the back-end, ensuring optimal resource usage.
 
 ### Opening NoMachine Desktop Sessions
 
-By default, when connecting to the **`merlin7-nx.psi.ch` front-end**, a new session automatically opens if none exists.
+When connecting to the `merlin7-nx.psi.ch` front-end, a new session automatically opens if no existing session is found. Users can manage their sessions as follows:
 
-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).
+- **Reconnect to an Existing Session**: If you have an active session, you can reconnect to it by selecting the appropriate icon in the NoMachine client interface. This allows you to resume work without losing any progress.
+![Open an existing Session]({{ "/images/NoMachine/screen_nx_single_session.png" }})
+- **Create a Second Session**: If you require a separate session, you can select the **`New Desktop`** button. This option creates a second session on another login node, provided the node is available and operational.
 
-![Open an existing Session]({{ "/images/NoMachine/screen_nx_existingsession.png" }})
+### Session Management Considerations
 
-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.
+- **Load Balancing**: The front-end service ensures that sessions are evenly distributed across the available back-end nodes to optimize performance and resource utilization.
+- **Session Limits**: Users are limited to one session per back-end node to maintain system stability and efficiency.
 
-![Open a New Desktop]({{ "/images/NoMachine/screen_nx_newsession.png" }})
+## Support and Resources
 
-### NoMachine LightDM Session Example
+If you encounter any issues or need further assistance with the Merlin7 NoMachine service, support is available via email. Please contact us at [merlin-admins@lists.psi.ch](mailto:merlin-admins@lists.psi.ch), and our support team will be happy to assist you.
 
-An example of the NoMachine session, which is based on [LightDM](https://github.com/canonical/lightdm) X Windows:
+### Advanced Display Settings
 
-![NoMachine Session: LightDM Desktop]({{ "/images/NoMachine/screen_nx11.png" }})
+NoMachine provides several options to optimize the display settings for better performance and clarity. These settings can be accessed and adjusted when creating a new session or by clicking the top right corner of a running session.
 
-## Accessing Merlin7 NoMachine from Outside PSI
+#### Prevent Rescaling
 
-### No Direct Access Without VPN
+Preventing rescaling can help eliminate "blurriness" in your display, though it may affect performance. Adjust these settings based on your performance needs:
 
-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
+- Display: Choose `Resize remote display` (forces 1:1 pixel sizes)
+- Display > Change settings > Quality: Choose medium-best quality
+- Display > Change settings > Modify the advanced display settings
   - Check: Disable network-adaptive display quality (turns off lossy compression)
-  - Check: Disable client-side image post-processing
+  - Check: Disable client side image post-processing