System Administration

Linux

Linux Network Monitoring

Here’s a list of some useful terminal based network monitoring utilties: https://askubuntu.com/q...

Linux: Impersonating Users

NOTE: This page was created to generalize the technique of impersonating a system account that ha...

Installing Node.js on Ubuntu

This page shows how to install Node.js on an Ubuntu 22 host. It only shows how to install a sing...

Ubuntu 22: Removing Existing Node.js

Ubuntu 22 comes with an existing version of node.js, v12, that is difficult to upgrade. This is ...

OpnSense Notes

Here’s a collection of notes and details for the house router setup. Build Software: OpnSense 2...

Supermicro Fan Problems

If you are running Noctua cooling fans in your PC and the PC is cycling fans up and down, then it...

Supermicro Fan Scripting

Some references: https://www.truenas.com/community/threads/script-hybrid-cpu-hd-fan-zone-control...

HowTo Retrieve Key and Cert from PFX

Here’s a good article on how to export SSL certificates, extract the key and certificate, and imp...

Linux Disk Usage

Linux has a few means to analyze a disk for space usage. One way, is a package called, ncdu. It...

Creating SSH Keys in Linux

Creating an SSH key is straightforward on a linux client, using this command: ssh-keygen By def...

Kali in VMWare

Here are some things for installing Kali in a VMWare VM. Adapted from here: https://www.kali.org...

Create PFX Cert File (for IIS)

Windows IIS requires a pfx file when importing an SSL certificate. This can be created from a cr...

Docker Space Full

Here are some things to check on when the disk on a docker host gets full sudo docker system p...

Ubuntu v24 Host Setup

Setting the Host Name Get the current hostname with this: hostnamectl To set it, use this: ...

Windows

Validating AD Machine Account

Here's a couple ways to validate the machine account of a PC in an Active Directory domain: dsre...

Generate SSL Cert

Here’s some steps on how to generate and setup an SSL certificate for a web site. First, ord...

Converting PEM to crt and key

If you receive pem formatted certificate and key files from a CA registrar, you will need to conv...

Convert SSL PFX for NGINX Usage

NGINX doesn’t natively use a pfx key file (pfx is what Windows IIS needs). So, it must be convert...

NTP Server

Here are some useful commands when running a GPS-disciplined NTP server. NTPQ When running a qu...

WSL Setup

In case it’s necessary to use Windows Subsystem for Linux, here’s a good tutorial on how to get i...

SSRS: Export Reports Without WebPortal

If you’re trying to export all the RDL, data sources, gif, and other files of a set of reports, b...

RunDeck Backups

Adapted from here: https://docs.rundeck.com/docs/administration/maintenance/backup.html We will ...

Ubuntu: Setup SSH Server

Here’s a short list of steps for setting up an SSH server in Ubuntu. Install SSH Server Install...

Ubuntu Service Creation (Systemd)

Below are instructions on how to setup a binary as a linux service. For additional systemd comma...

SystemCtl Usage

Below is a list of commonly used systemd commands. If you are needing to configure a binary as a...

UFW and Docker

When running containers in Docker, you will come across the need for a container to gain access t...

Docker Commands

Here’s a list of commands to remember for docker administration. List Containers To list all do...

SSH Keys

SSH Key Naming Convention

This page describes a good naming convention for SSH keys, that makes them easier to track, rotat...

How to Get Host SSH Key Fingerprints

Here’s a short command line statement that will fetch the host ssh key fingerpring without authen...

Creating SSH Keys in Windows

General Notes SSH keys can be easily generated in Windows, using PuttyGen. See this article for...

Permission Denied while Copying SSH Key for New User

When setting up a new host, you will come across the need to copy SSH keys to it. This is easy t...