stress-ng — Installation

stress-ng is a Linux kernel stress tool installed directly on target nodes using the standard package manager. There is no dedicated Install-StressNg.ps1 script; the runner orchestrates test execution over SSH once the package is installed.

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Prerequisites

Requirement	Details
Target OS	Ubuntu 22.04 / Rocky Linux 9 (or any systemd Linux with apt or dnf)
stress-ng version	0.15.00 or later
Runner OS	Windows Server 2022 with PowerShell 7.3+
SSH access	Key-based auth; linux_ssh credential in variables file
Results directory	Created automatically at /tmp/stress-ng-results/<RunId>/
Ansible	Not required — SSH commands issued directly from PowerShell via ssh.exe

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Installing stress-ng on Target Nodes

Ubuntu / Debian

sudo apt-get update -qq
sudo apt-get install -y stress-ng

# Verify
stress-ng --version
# stress-ng, version 0.15.06

Rocky Linux / RHEL

sudo dnf install -y epel-release
sudo dnf install -y stress-ng

stress-ng --version

Verify Across All Cluster Nodes

From the runner, iterate over all target nodes defined in your variables file:

$nodes = @("hci01-node1", "hci01-node2", "hci01-node3", "hci01-node4")
$sshUser = "azurelocaladmin"

foreach ($node in $nodes) {
    $ver = ssh -i "$env:USERPROFILE\.ssh\azurelocal_rsa" `
               -o BatchMode=yes `
               "$sshUser@$node" "stress-ng --version 2>&1"
    Write-Host "$node: $ver"
}

Expected output:

hci01-node1: stress-ng, version 0.15.06
hci01-node2: stress-ng, version 0.15.06
hci01-node3: stress-ng, version 0.15.06
hci01-node4: stress-ng, version 0.15.06

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SSH Key Configuration

Start-StressNgTest.ps1 connects to each node as the non-root SSH user defined in your cluster variables file. The key pair must be pre-distributed.

# Generate key pair once on the runner (if not already present)
ssh-keygen -t ed25519 -f "$env:USERPROFILE\.ssh\azurelocal_rsa" -C "azurelocal-loadtools"

# Distribute to each node
foreach ($node in @("hci01-node1","hci01-node2","hci01-node3","hci01-node4")) {
    ssh-copy-id -i "$env:USERPROFILE\.ssh\azurelocal_rsa.pub" `
                "azurelocaladmin@$node"
}

Set the linux_ssh credential block in your variables file:

# config/variables.yml
credentials:
  linux_ssh:
    username: azurelocaladmin
    private_key_path: C:\Users\RunnerUser\.ssh\azurelocal_rsa

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Remote Paths Created at Runtime

Path	Purpose
/tmp/stress-ng-results/<RunId>/	Per-run results directory (created by Start-StressNgTest.ps1)
/tmp/stress-ng-results/<RunId>/stress-ng-results.yml	Raw stress-ng YAML output per node

These directories are created on each target node by the test script via SSH; no manual creation is required.

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Verifying readiness before a run

# Quick pre-flight: confirm stress-ng responds and sudo is passwordless for kill signals
ssh -i "$env:USERPROFILE\.ssh\azurelocal_rsa" `
    -o BatchMode=yes `
    "azurelocaladmin@hci01-node1" `
    "stress-ng --cpu 1 --timeout 2s --metrics-brief 2>&1 | tail -3"

A healthy response ends with a line similar to:

stress-ng: info:  [12345] successful run completed in 2.00s (1 stressor spawned)