Sysadmin Casts - simple bite sized sysadmin screencasts (released twice-weekly)

Browse Episodes

Anatomy of a SQL Injection Attack leading to Code Execution

#21 - Anatomy of a SQL Injection Attack leading to Code Execution (Duration: 15 minutes, Published: Jan 02, 2014)

In this episode, I am going to show you what a SQL injection attack is, along with how it works, and then we will look at several methods to prevent them. We will also look at how a SQL injection attack can reach far beyond the database.

How to write an Incident Report / Postmortem

#20 - How to write an Incident Report / Postmortem (Duration: 5 minutes, Published: Nov 19, 2013)

In this episode, I wanted to look at how to write an Incident Report, also referred to as a Postmortem. Rather than give you something of my own creation, lets look at a Google Incident Report from early 2013, which I think serves as a great example.

Crash Course on Man Pages

#19 - Crash Course on Man Pages (Duration: 6 minutes, Published: Nov 14, 2013)

In this episode, I wanted to look at how we can use the man command to view manual pages for various commands, configuration files, and system libraries.

Managing Iptables with Puppet

#18 - Managing Iptables with Puppet (Duration: 13 minutes, Published: Nov 12, 2013)

In this episode, I wanted to show you the Puppet Labs Firewall module. We are going to use what we learned in episode #8, about Vagrant and Puppet, and apply that to managing iptables firewall rules with Puppet.

Why you should use a Wiki

#17 - Why you should use a Wiki (Duration: 13 minutes, Published: Nov 07, 2013)

In this episode, I wanted to talk about why you should be using a Wiki for keeping track of internal documents, policies and procures, as well as other information about your infrastructure, then in the latter part of the episode, we will cover how to install MediaWiki on a CentOS 6.4 box.

Hard and Symbolic Links

#16 - Hard and Symbolic Links (Duration: 10 minutes, Published: Nov 04, 2013)

In this episode, I wanted to talk about the differences between hard and symbolic links. We will look at why links are useful, the pros and cons of hard vs symbolic links, then have a look under the hood at inodes and filesystem metadata to see how links actually work.

The IT Disconnect

#15 - The IT Disconnect (Duration: 9 minutes, Published: Oct 07, 2013)

In this episode, I wanted to do something a little different, rather than highlight a piece of technology, I wanted to talk about how IT should be proactively improving communication with other departments within your organization.

Introduction to Linux Control Groups (Cgroups)

#14 - Introduction to Linux Control Groups (Cgroups) (Duration: 20 minutes, Published: Oct 03, 2013)

In this episode we are going to review Control Groups (cgroups), which provide a mechanism for easily managing and monitoring system resources, by partitioning things like cpu time, system memory, disk and network bandwidth, into groups, then assigning tasks to those groups.

Crash Course on Common Commands

#13 - Crash Course on Common Commands (Duration: 11 minutes, Published: Aug 20, 2013)

In this episode, I will give you a crash course on how to use common commands for getting around the filesystem, reviewing running processes, looking at disk utilization, and editing files.

Crash Course on the Filesystem Hierarchy Standard

#12 - Crash Course on the Filesystem Hierarchy Standard (Duration: 7 minutes, Published: Aug 15, 2013)

In this episode, I will give you a crash course on the Filesystem Hierarchy Standard (FHS). The Filesystem Hierarchy Standard gives a great overview of what a UNIX-like filesystem should look like, for example, what directories should exist, and what their contents should be.

Internal Git server with Gitolite

#11 - Internal Git server with Gitolite (Duration: 13 minutes, Published: Jul 29, 2013)

In this episode I wanted to talk about setting up a central Git sever and using Gitolite to manage user access. You might put this on an internal company network, where you and your colleagues can develop together.

Openfire XMPP/Jabber on CentOS

#10 - Openfire XMPP/Jabber on CentOS (Duration: 14 minutes, Published: Jul 20, 2013)

In this episode, I wanted to talk about setting up the Openfire XMPP server on CentOS. Lets say, for example, that you want to improve internal communication around the office, you might want to try an internal XMPP server, because it allows you to quickly chat with colleagues via instant messages.

Yum Versionlock

#9 - Yum Versionlock (Duration: 4 minutes, Published: Jul 03, 2013)

In this episode, we will look at a method for locking rpm packages at a particular version. For example, that you have a package installed on a server, and that a package update is coming, which will likely break your configuration. You would like to somehow exclude this package from getting updated. We will use a yum plugin called versionlock to solve this problem.

Learning Puppet with Vagrant

#8 - Learning Puppet with Vagrant (Duration: 13 minutes, Published: Jun 25, 2013)

In this episode I wanted to introduce you to Puppet. Puppet allows you to quickly automate many sysadmin tasks, like deploying new machines, pushing changes out to existing machines, and helps you verify the configs of existing machines. We will also be setting up development environment for testing and playing around with puppet using Vagrant.

Why you should use a password safe

#7 - Why you should use a password safe (Duration: 4 minutes, Published: Jun 18, 2013)

In this episode we are going to take a look at centralized password management. How a password safe can be a simple and effective tool for you and your team, and why you should be using one.

Locate files by name

#6 - Locate files by name (Duration: 3 minutes, Published: Jun 09, 2013)

In this episode we are going to review the locate and updatedb commands provided by the mlocate package. Locate is a useful command for finding files quickly. We will also look at updatedb.conf, reviewing the PRUNEPATHS option, using this to limit the stress on your servers.

Create a Vagrant box with Veewee

#5 - Create a Vagrant box with Veewee (Duration: 9 minutes, Published: Jun 05, 2013)

In this episode we will create a Vagrant box with Veewee. We will use Veewee to create a working Vagrant SL (Scientific Linux) 6.4 box from a SL 6.3 template. I'll demonstrate the process end-to-end. This process should work with RHEL and CentOS too.

Vagrant

#4 - Vagrant (Duration: 5 minutes, Published: May 31, 2013)

In this episode we will review Vagrant. Vagrant makes it easy to create disposable environments for testing scripts and infrastructure changes.

SystemRescueCd

#3 - SystemRescueCd (Duration: 3 minutes, Published: May 05, 2013)

In this episode we will review SystemRescueCd. SystemRescueCd is a very handy tool for troubleshooting problem. I've used it to re-install grub boot menus, transfer files from nonbootable machines, and a host of other issue. You can also use SystemRescueCd to launch Memtest86+ and DBAN.

RPM Changelog

#2 - RPM Changelog (Duration: 3 minutes, Published: May 04, 2013)

In this episode we will learn how to query and review rpm package information and the changelog history. This can be very helpful in determining whether a bug or CVE security issue has been fixed in a given rpm package.

VirtualBox and CentOS 6.3

#1 - VirtualBox and CentOS 6.3 (Duration: 4 minutes, Published: Apr 19, 2013)

In this episode we will use Oracle's VirtualBox to create a CentOS 6.3 virtual machine. Follow along as I download the install media, create a new virtual machine, and install CentOS 6.3. You can also download the CentOS 6.3 virtual machine which was created in this episode.