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

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Introduction to Docker

#31 - Introduction to Docker (Duration: 16 minutes, Published: Jul 28, 2014)

In this episode, we are going to be looking at Docker. I have broken this episode into two sections. First, we will cover what Docker is at a high level and touch on the container workflow. Second, we will look at a live demo of Docker in action.

CLI Monday: lsof

#30 - CLI Monday: lsof (Duration: 8 minutes, Published: Jul 21, 2014)

In this episode, I wanted to show you the lsof command. We are going to review several issues and how the lsof command can be used to troubleshoot what is going on.

Introduction to Amazon Web Services (AWS)

#29 - Introduction to Amazon Web Services (AWS) (Duration: 9 minutes, Published: Jul 19, 2014)

In this episode, I wanted to give you an introduction to Amazon Web Services (commonly referred to as AWS). AWS is one of the premier cloud providers, which is drastically changing the way many think about IT. This introductory episode lays the foundation for more advanced AWS episodes to come.

CLI Monday: cat, grep, awk, sort, and uniq

#28 - CLI Monday: cat, grep, awk, sort, and uniq (Duration: 9 minutes, Published: Jul 14, 2014)

In this episode, I would like to show you a series of commands for reviewing log data, how to extract event counts from that data, and finally how to create sparklines from those counts. This can be extremely useful for pointing you in the right direction while troubleshooting issues.

LVM Linear vs Striped Logical Volumes

#27 - LVM Linear vs Striped Logical Volumes (Duration: 16 minutes, Published: Jul 08, 2014)

In this episode, I wanted to look at the performance characteristics between linear and striped logical volumes using LVM. We will examine what is happening behind the scenes along with some preliminary benchmarks using an AWS i2.8xlarge instance with 8x800GB SSD disks, 244GB of RAM, and 32 virtual cores.

CLI Monday: head, tail, and wc

#26 - CLI Monday: head, tail, and wc (Duration: 4 minutes, Published: Jul 07, 2014)

In this episode, I wanted to introduce a new episode type called CLI Monday. The idea being, we will review useful command line utilities every Monday. Today, we are going to review the head, tail, and wc commands.

Bits Sysadmins Should Know

#25 - Bits Sysadmins Should Know (Published: May 27, 2014)

The following is a crash course on what I think goes into the making of a well rounded Linux Sysadmin. This episode is a semi-organized brain dump of bits I have learned throughout my career, which will be used as a type of guide, or road map, for future episodes on this site.

Introduction to Containers on Linux using LXC

#24 - Introduction to Containers on Linux using LXC (Duration: 15 minutes, Published: Apr 30, 2014)

In this episode, I wanted to give you an Introduction to Containers on Linux using LXC. We will look at what Containers are as a concept, why they are useful, and then move onto a live demo of what a Container looks like on a real system using LXC.

Root Privileges and Automated Tasks

#23 - Root Privileges and Automated Tasks (Duration: 7 minutes, Published: Apr 27, 2014)

In this episode, we will discuss giving automated tasks narrow root privileges via the sudo command using the nopasswd option.

Common Archive and Compression Formats

#22 - Common Archive and Compression Formats (Duration: 11 minutes, Published: Apr 24, 2014)

In this episode, I wanted to talk about common archive and compression formats that you are likely to encounter on Linux machines. We will review the differences between archive and compression formats and then focus on how to create and extract these formats using various utilities.

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 procedures, 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.