Scenario We have a router/firewall with two NICs one used to connect to the Internet (WAN) and the other to connect to the local network (LAN). We would like to beef up the security aspect of our site and introduce a Demilitarized Zone (DMZ). If this should be implemented without the use of vlans we…
Tag: Linux
Simple ZFS Mirrored file system…
Introduction: In this blog post we are going to create a Mirrored file system using ZFS. We are going to use 5 Disks, 4 for data and 1 as a hot spare. The disks will be 200GB with a combined size of 1TB, but acutal usable space will only be 400GB. This file system has…
PHP… Do Not Run if running…
If you are creating an application that will be run in the terminal on a Linux machine and you don’t want it to run if its already running you can use the same code below to achieve this. class pid { protected $filename; public $already_running = false; function __construct($directory) { $this->filename = $directory . ‘/’ . basename($_SERVER[‘PHP_SELF’]) . ‘.pid’;…
Cat Linux Command
The cat Linux command is used to display file contents, for example if I quickly wanted to see the contents of a text file I would use the cat command to dump the output to the console or pipe it to another command. Situations when the cat Linux command would used How To dump the…
How To setup SSH Key Authentication on Linux
This short tutorial explains how to setup SSH to use key based authentication, by default on CentOS this is disabled. To start with follow our guide on how to generate SSH key pairs and copy the key over. Configure SSH to enable Public Key Based Authentication Open up /etc/sshd_config in vi and find the following…
Ubuntu 12.04 Release Date
With the Ubuntu 12.04 release date just around the corner and the release in final beta we should be expecting a release date any day now, the estimated release date for 12.04 Precise Pangolin is the 26th of April 2012. Until then you might want to download Ubuntu 12.04 using our instructions, just so long…
How To Upgrade to Ubuntu 12.04 for Desktops & Servers running 10.04 or 11.10
This post contains full instructions on how to upgrade to Ubuntu 12.04 from 10.04 or 11.10 for servers and desktops I have included both GUI and command line upgrade instructions for Ubuntu 12.04 updates. If you have any 3rd party propriatory graphics card drivers installed it is recommended you remove them prior to the upgrade…
Recursive Grep Command – Recursively Search Through Directories
How to perform a recursive grep on Linux, allowing you to search through files / sub directories for a specific string. How to grep recursively grep -r SEARCHSTRING /home/* Enter your own search in the SEARCHSTRING above… Say for example I am searching for the string class=”author” located somewhere in /var/www/wp-content/themes/your-theme. I would type the…
how you can make files on your system immutable…
Here is a cool tip on how you can make files on your system immutable. By immutable, I mean evenroot can’t delete the files if he choose to. Linux ships with a tool called chattr which can be used for the purpose. ‘chattr’ is similar to the ‘attrib’ DOS equivalent tool but much more powerful and flexible. To make your file…
Kubuntu going away? Doubtful.
I’m sure everyone has seen the proverbial “nail-in-the-coffin” for the big blue gears, but Kubuntu is a largely populated distribution that I think it going to bounce right back. Kubuntu is a Ubuntu based distribution that opened it’s doors seven years ago with version 5.04. It has often been on the bleeding edge of KDE…