sysadmin

I’m always interested to talk to college students about technology and business in general.

Keeping current with the latest trends and technologies in the realm of information security is critical and there are many options to choose from.

One of the first tools I learned about after working with Red Hat was sysstat.

We’re all familiar with live booting Linux distributions.

Citrix has some helpful documentation online about configuring remote syslog support for XenServer using the XenCenter GUI.

It seems like everyone is embracing systemd these days.

During one of my regular trips to reddit, I stumbled upon an amazingly helpful Linux I/O stack diagram:

Amid all of the Docker buzz at the Red Hat Summit, Project Atomic was launched.

The openssl heartbleed bug has made the rounds today and there are two new testing builds or openssl out for Fedora 19 and 20:

I’ve written about installing Xen on Fedora 19 and earlier versions on this blog before.

It’s been three long years since the last MySQLTuner release but you’ll now find version 1.

I figured that the Puppy Linux and icanhazip.

Many of the non-technical posts on the blog are inspired by the comments of others.

I’ve made posts about the DevOps Weekly mailing list before.

My SANS classmates were learning how to set and recognize file permissions on a Linux server and we realized it would be helpful to display the octal value of the permissions next to the normal rwx display.

In my previous post about installing Fedora via PXE, I forgot to mention a big time saver for the installation.

This post has been a bit delayed, but I want to follow up on the post I wrote last month about moving from OS X to Linux at work.

If you run bwm-ng and you’ve run a yum upgrade lately on Fedora 19, you have probably seen this:

The thought of using Linux as a manager in a highly Windows- and Mac-centric corporate environment isn’t something to be taken lightly.

Outside of the RHCA exams, I haven’t configured a PXE system for my personal needs.

After my podcast interview at the 2013 Red Hat Summit, Dan Walsh posted a photo of himself in the SELinux shirt that I gave him at the Summit:

The confined user support in SELinux is handy for ensuring that users aren’t able to do something that they shouldn’t.

David Egts and Gunnar Hellekson were kind enough to invite me to participate in their Dave and Gunnar Show podcast during the 2013 Red Hat Summit.

Most of my websites run on a pair of Supermicro servers that I purchased from Silicon Mechanics (and I can’t say enough good things about them and their servers).

It’s been a little while since I last posted about installing Xen on Fedora, so I figured that Fedora 19’s beta release was as good a time as any to write a new post.

This post is a quick one but I wanted to share it since I taught it to someone new today.

Changing my ssh port from the default port (22) has been one of my standard processes for quite some time when I build new servers or virtual machines.

The wheel group exists for a critical purpose and Wikipedia has a concise definition:

I’m in the process of moving back to a postfix/dovecot setup for hosting my own mail and I wanted a way to remove the more sensitive email headers that are normally generated when I send mail.

I dragged out an old Aopen MP57-D tonight that was just sitting in the closet and decided to load up kvm on Fedora 18.

It’s no secret that Google Reader is a popular way to keep up with your RSS feeds, but it’s getting shelved later this year.

After adding some upgrades for icanhazip.

I had a peculiar situation today where I cloned a repository into a directory which was inside another repository.

This post covers the second half of my experience moving back to a Linux desktop but I figured it was a good opportunity to focus on the ThinkPad T430s itself as well as the Lenovo ordering experience.

Although I’ve been exclusively using a Mac for everything but servers since about 2008, I found myself considering a move back to Linux on the desktop after seeing how some people were using it at LinuxCon.

Automating package updates in CentOS 6 is a quick process and it ensures that your system receives the latest available security patches, bugfixes and enhancements.

I was sitting at my desk yesterday when I saw a tweet from @LinuxFoundation:

After a recent issue I had with some users in the Puppy Linux forums, I thought it might be prudent to write a post about how to monitor and protect your reputation online.

A forum thread cropped in my inbox today from the Puppy Linux forums titled “Major Hayden?

Vitalie Cherpec contacted me back in May about his new hosted DNS offering, Luadns.

Although GRUB 2 does give us some nice benefits, changing its configuration can be a bit of a challenge if you’re used to working with the original GRUB for many, many years.

LVM snapshots can be really handy when you’re trying to take a backup of a running virtual machine.

This problem came up in conversation earlier this week and I realized that I’d never written a post about it.

If you try to run Xen without libvirt on Fedora 17 with SELinux in enforcing mode, you’ll be butting heads with SELinux in no time.

Thursday has felt like the busiest, most jam-packed day of the week.

Wednesday was action-packed with dramatic keynotes and great sessions.

I’m on my way to my first Red Hat Summit and I’m really eager to learn some new things, meet new people, and share my experiences with others.

Anyone who has been a system administrator for even a short length of time has probably used traceroute at least once.

The feedback from my last lengthy post (Lessons learned in the ambulance pay dividends in the datacenter) about analogies between EMS and server administration was mostly positive, so I decided to do it again!

While cleaning up a room at home in preparation for some new flooring, I found my original documents from when I first became certified as an Emergency Medical Technician (EMT) in Texas.

Kristóf Kovács has a fantastic post about some lesser-known Linux tools that can really come in handy in different situations.

I originally wrote this post for the Rackspace Blog but I decided to post it here in case some of my readers might have missed it.

I originally wrote this post for the Rackspace Blog but I’ve posted it here just in case anyone following my blog’s feed finds it useful.

Today marks the fifth year that this blog has existed on the internet.

The grades came back last Friday and I’ve passed the last exam in the requirements to become a Red Hat Certified Architect (RHCA).

Getting Fedora 16 working in XenServer isn’t the easiest thing to do, but I’ve put together a repository on GitHub that should help.

One of the handiest tools in the OpenSSL toolbox is s_client.

As promised in my earlier post entitled Kerberos for haters, I’ve assembled the simplest possible guide to get Kerberos up an running on two CentOS 5 servers.

Regular users of Python’s package tools like pip or easy_install are probably familiar with the PyPi repository.

I used to be one of those folks who would install Fedora, CentOS, Scientific Linux, or Red Hat and disable SELinux during the installation.

If you want to forward e-mail from root to another user, you can usually place a .

Before we get started, I really ought to drop this here:

Fedora 15 was released with some updates to allow for consistent network device names.

SELinux isn’t a technology that’s easy to tackle for newcomers.

I’m using SELinux more often now on my Fedora 15 installations and I came up against a peculiar issue today on a new server.

Standard e-mail etiquette is pretty obvious to most of us and if you’re good at it, you’ll get your point across more often without stepping on toes or causing unneeded confusion.

Before I get started, I’d like to give a big thanks to all of the visitors who dropped by and participated in the contest last week.

Quite a few people who couldn’t make it to Xen Summit 2011 this year asked me to write a post summarizing my takeaways from the event.

If you haven’t noticed already, full Xen dom0 support was added in the Linux 3.

This is a copy of a post I wrote for the Rackspace Talent blog.

Some might call me paranoid, but I get nervous when my package manager automatically removes a kernel.

If you work for a growing company like I do, it’s inevitable that you’ll have to do your fair share of interviewing.

There are few things which will rattle systems administrators more than a compromised server.

As promised in one of my previous posts about dual-primary DRBD and OCFS2, I’ve compiled a step-by-step guide for Fedora.

Although it’s not a glamorous subject for system administrators, backups are necessary for any production environment.

While I’m not the biggest proponent of certifications, I still think you can learn some valuable information while studying for some certification tests.

My daily work requires me to work with a lot of customer data and much of it involves IP address allocations.

This situation might not affect everyone, but it struck me today and left me scratching my head.

It’s not easy remembering which RPM packages contain certain files.

One of the most interesting topics I’ve seen so far during my RHCA training at Rackspace this week is SystemTap.

The guide to redundant cloud hosting that I wrote recently will need some adjustments as I’ve fallen hard for the performance and reliability of DRBD and OCFS2.

For those of us in the United States, we celebrate Thanksgiving today.

The pv command is one that I really enjoy using but it’s also one that I often forget about.

If you offer a web service that users query via scripts or other applications, you’ll probably find that some people will begin to abuse the service.

Diagram: OpenVPN to Rackspace Cloud Servers and Slicehost

Last night’s post about my charity drive for the Movember Foundation was the 400th post on my blog!

As my uptime reports have shown, and as some of you have reported, my blog’s load time has increased steadily over the past few weeks.

On most systems, using Fedora’s preupgrade package is the most reliable way to update to the next Fedora release.

After a discussion amongst coworkers about professional certifications in e-mail signatures yesterday, I decided to throw the question out to Twitter to gather some feedback:

One of the most common questions that I see in my favorite IRC channel is: “How can I secure sshd on my server?

Installing Xen can be a bit of a challenge for a beginner and it’s made especially difficult by distribution vendors who aren’t eager to include it in their current releases.

Let’s go ahead and get this out of the way: The following post contains only my personal opinions.

I’ve been getting requests for GlusterFS benchmarks from every direction lately and I’ve been a bit slow on getting them done.

As many of you might have noticed from my previous GlusterFS blog post and my various tweets, I’ve been working with GlusterFS in production for my personal hosting needs for just over a month.

After I wrote a recent post on best practices for iptables, I noticed that I forgot to mention comments for iptables rules.

Typical configuration for a proxy-type load balancer

NOTE: This post is out of date and is relevant only for GlusterFS 2.

I’ll admit it right now: I love engaging customers and learning more about how what we do at Rackspace can help their business or ideas take flight.