SysAdmin

tcpdump fu

Packet capture is one of the most fundamental and powerful ways to do network analysis. You can learn virtually anything about what is going on within a network by intercepting and examining the raw data that crosses it. Modern network analysis tools are able to capture, interpret and describe this network traffic in a human-friendly manner.

Linux Systems Capacity Planning

This video is from our good friends at USENIX's recent LISA conference in Boston. "Linux Systems Capacity Planning: Beyond RRD and top", by Rodrigo Campos

The Lustre Distributed Filesystem

There comes a time in a network or storage administrator's career when a large collection of storage volumes needs to be pooled together and distributed within a clustered or multiple client network, while maintaining high performance with little to no bottlenecks when accessing the same files. That is where Lustre comes into the picture. The Lustre

Getting Help From Linux - Part 2 Info

Well here we are again, at part two of the 'Getting Help from Linux' series.  In this blog post I'll be talking about using Info to get help from Linux.  In my previous post I spoke about how Info came about, but just in case you missed it I'll give you another quick lesson.  Gnu

Tracking Server Uptimes

Unlike some other OS's, Linux almost never has to reboot… or so I was told when I first started learning about it. To illustrate the point, my mentor introduced me to an app that he ran on all of his servers called uptimed.

Unboxing Day

As much as I love working with Linux and configuring software, one major part of being a sysadmin that always has appealed to me is working with actual hardware. There's something about working with tangible, physical servers that gives my job an extra dimension and grounds it from what might otherwise be a completely abstract job even further disconnected from reality.

Remotely Wipe a Server

In many ways, I feel sorry for people stuck with proprietary operating systems. When something goes wrong or if they have a problem to solve, the solution either is obvious, requires buying special software or is impossible. With Linux, I've always felt that I was limited only by my own programming and problem-solving abilities, no matter what problem presented itself.

Lock Firefox 6 Prefs (Also versions 3, 4, & 5)

In a corporate environment, it's often important to enforce Internet proxy settings for all users. Setting those options automatically is often difficult. Making them locked and immutable is even more difficult and poorly documented. Today we'll learn the basics, and from there you can customize Firefox as much or as little as you like.

Creating a Centralized Syslog Server

A centralized syslog server was one of the first true SysAdmin tasks that I was given as a Linux Administrator way back in 1997. My boss at the time wanted to pull in log files from various appliances and have me use regexp to search them for certain key words. At the time Linux was still in its infancy, and I had just been dabbling with it in my free time.

It's Always DNS's Fault!

It's always better to learn from someone else's mistakes than from your own. In this column, Kyle Rankin or Bill Childers tells a story from his years as a systems administrator, and the other chimes in from time to time. It's a win-win: you get to learn from their experiences, and they get to make snide comments to each other. Today's episode is narrated by Bill.

Nagging Notifications

In the February 2011 issue, I wrote about screen, the console window manager, and how I configure its hardstatus line to show notifications along the bottom of my terminal window.

Getting Help from Linux - Part 1 Man Pages

man womanNo manual entry for woman Oooh, I just know I'm going to hear it in the comments for that one. But you know what? Just how many of you have tried something similar with other words? You know you have at least once or twice. Go ahead, try one or two..you might be surprised.

Creating Software-backed iSCSI Targets in Red Hat Enterprise Linux 6

Studying for certification exams can be an adventure. Even more so when the certification exam is a hands-on, performance-based exam. The quandry most people I know fall into, is that to effectively study for such an exam, you need access to a lab environment with elements that may be beyond the scope of the average Linux enthusiast. One such element is iSCSI. 

Archiving CDs to ISO from the Command Line

A few weeks ago I was working on a PC when I needed to grab the motherboard driver CD.  In a perfect world, the CD would be located in a nice protective sleeve, safely kept away from the nasty elements that encompass the IT tech area (read: coffee, scratches, and the occasional jelly doughnut).  But in this case, it appeared someone had taken this CD and wiped it a

Fun with ethtool

Time to be honest here for a minute. The open source community really has outdone themselves coming up with some very obscure names for packages. Let's take this list of packages for instance: emacs, gimp, gcc, mutt, grub, kyle rankin, parted, tar, mutt, vim. Nine times out of ten, a common person is going to look at that list and become utterly confused over what package does what.

Hacking, Old-School

When you mention hacking in the general public, the image most people think of is a nerdy guy breaking into a computer system from his bedroom. This month, I take a look at some of the tools available to do exactly that. Of course, this is for information purposes only, so please don't do anything nasty. Remember, with great power comes great responsibility.

Creating Custom Man Pages

Man pages have been the primary source for UN*x documentation for a long time. Whenever I create a script that's going to be around for a while, I create documentation in the form of a section 1 man page. This stops my cell phone from ringing on the weekends when the junior sysadmins are looking for my notes.

Centralized Logging with a Web Interface

Wouldn’t it be nice if you had a web interface to the logs on your central log server? Well, dream no more because this one is a reality thanks to LogAnalyzer (aka phplogcon). Let's take a look at how to setup both it and its suggested syslog variant, rsyslog, on a central log server.