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March 2, 2022 – 2:00 pm

Books have been written on the subject of awk and sed. Here’s a small sample of commands I put together over the years that are useful for everyday system administration tasks. Most of these tasks …

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Article Archive for February 2013

Fast IP Range Scanner in Bash

February 22, 2013 – 2:53 pm
ping_pong-wallpaper-960x600

Just a simple script to scan an IP range and do a reverse DNS lookup. This can be useful for building an inventory of systems on your LAN. Just make sure to give your network …

openlava Quick Test

February 22, 2013 – 12:46 pm
bar_001

After years working with PBS and LSF, ran into Jeff Layton’s “Share the Load” review of openlava resource manager in the Feb 2013 issue of the Admin Magazine and nostalgia took over. So I built …

Secure Data Destruction for Unix

February 21, 2013 – 11:45 pm

What is secure computer data destruction? Simply put, securely-deleted data cannot be recovered by any known technique. But when it comes to data security, things are rarely simple. New data recovery methods are developed every …

SEO for Unix Geeks

February 21, 2013 – 11:45 pm
Traffic light for bikes.

So, you are finally done with your new shiny Web site and looking for ecom site integration. Congratulations. There is one small problem: the only two visitors to the site are you and Googlebot. And …

Selecting CMS Software

February 21, 2013 – 11:45 pm
wp-newspaper

If you are looking for an open-source content management system, your choices are likely to boil down to these three: Joomla!, WordPress, and Drupal. Professional CMS developers tend to disregard WordPress as a purely blogging …

Protected: KW MSP-10X Prototype

February 21, 2013 – 11:45 pm

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Jailbreaking My iPhone 4S

February 21, 2013 – 11:45 pm
apple

An iPhone 4S is a fairly sophisticated computer capable of doing many interesting things. Unfortunately, since most phone users are computer idiots, to preserve its bottom line and the sanity of its tech support staff, Apple imposes severe limitations on what you, as a user, can do with your iPhone or iPad. As a Unix sysadmin I am entirely on Apple’s side on this one. However, it would have been nice if Apple allowed an option of full access in exchange for voluntarily voiding the warranty. For those of us who know what they are doing and are not gonna run in tears to the nearest Genius Bar if something goes wrong…

SSH Login Without Password for a Linux Cluster

February 21, 2013 – 11:45 pm
Computer Password Security

Most HPC cluster management utilities will automatically take care of the password-less SSH configuration. However, if you are not so lucky, here are the simple steps to get this working. Keep in mind that, depending …

Filesystem Performance Testing Using dd

February 5, 2013 – 3:35 pm
Shell Script

Below is a simple script to test filesystem read/write performance using dd with varying blocksize parameter. This can be useful for testing local filesystems as well as network-mounted filesystems. The end result will be a …