How to Install Lustre on NixOS Latest

Lustre is a high-performance, distributed filesystem designed for large-scale, high-bandwidth environments. In this tutorial, we will walk you through the process of installing Lustre on the latest version of NixOS.

Prerequisites

Before you begin, you will need:

A machine running the latest version of NixOS.
Root access to the machine.

Step 1: Install the Lustre packages

Open a terminal window and log in as root.
Run the following command to update the package manager:
```
nix-channel --update
```
Run the following command to install the Lustre packages:
```
nix-env -iA \
nixos.lustre-client \
nixos.lustre-server \
nixos.lustre-tests
```
This will install Lustre client, server, and test packages.

Step 2: Configure the Lustre services

Open a terminal window and log in as root.
Edit the configuration file for the Lustre servers:
```
nixos-rebuild edit-config -I nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/nixos-unstable.tar.gz nixos
```
This will open the configuration.nix file in your default text editor.

Add the following lines to the services.lustre section of the configuration.nix file:

services.lustre = {

server.enable = true;

server.options = {
mkfs.options = "-jmdt /dev/sdc mkfs.lustre";
host = "your-lustre-server-hostname";
mgs_disk = "/dev/sdc";
mgs.heuristic_targets = [{ host = "your-lustre-server-hostname"; }];
};
 
 client.enable = true;

 client.options = 
 {
 defaults.extraModprobeConf = "options lnet networks=tcp(nic)<eth0>";
 host = "your-lustre-server-hostname@tcp0";
 };
 
 }

Replace "your-lustre-server-hostname" with the hostname of your Lustre server. The mkfs.options line is used to specify the Lustre filesystem's layout options.

Save and close the configuration.nix file.
Run the following command to reload the NixOS configuration:
```
nixos-rebuild switch
```

Step 3: Create the Lustre file system

Open a terminal window and log in as root.
Run the following command to create the Lustre filesystem:
```
sudo mkfs.lustre --mgs --mdt --fsname=lustre --reformat --backfstype=ldiskfs --mkfsoptions='-J size=128M' /dev/sdc
```
Replace "/dev/sdc" with the device name of the disk you want to use for the Lustre filesystem.
Create the mount point for the Lustre filesystem:
```
sudo mkdir /mnt/lustre
```

Mount the Lustre filesystem:

sudo mount -t lustre /dev/sdc /mnt/lustre

Verify that the Lustre filesystem is mounted:
```
df -hT
```
You should see the Lustre filesystem listed in the output.

Step 4: Test the Lustre installation

Open a terminal window and log in as root.
Run the following command to verify that the Lustre server is running:
```
sudo lctl list_nids
```
You should see the hostname of the Lustre server listed in the output.
Run the following command to verify that the Lustre client is able to connect to the server:
```
sudo lfs df
```
You should see the Lustre filesystem listed in the output.

Congratulations! You have successfully installed Lustre on NixOS Latest. You can now use Lustre to manage large-scale, high-bandwidth distributed filesystems.