Recently, I set up vsftpd on RHEL5 with SSL and it was significantly easier than I had suspected it would be. I wanted to quickly share the methods I used to set up the server, test from a client, and verfiy everything was encrypted.
Category: Articles
Decade of Storage: Analysis of Data Costs
Yesterday, I noticed this interesting tidbit from Rackspace calculating the cost of data over the last Decade of Storage. Of course, there a few bumps in the road that made me chuckle. Interestingly, in the last couple of years it plots the cost from $0.40/GB to $0.06/GB. This ties together a whole bunch of things that I have thought about over the last couple of years. First, now is a wonderful time to be a user buying storage for personal audio and video. Second, regular people are going to have to start to learn data management strategies. Finally, this cost isn’t even close to what it is for me in my data center. It is easy for us to celebrate the cheap cost of raw storage while loosing track of the total cost of ownership for data. I will elaborate.
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Passion for the Science of Computing
I recently read an article called “Computer. Science. Paradox?” by Ben Rockwood which pointed me to a phenomenal project called “Great Principles of Computing.” The project’s founding principle is that Computing, not Computers are the center of our study and that the Science of Computing is, indeed, a natural science. This project touches on so many issues in the teaching of Computer Science and how we index our knowledge. It also provides solutions to so many frustrations I felt while working my way through the undergraduate Computer Science curriculum at the University of Akron.
Systems Administrator’s Lab: OpenSSH MaxStartups
Background When performing automation using OpenSSH/Cron you will inevitably run into concurrency problems. Recently, we had a problem where one machine was receiving 21 ssh connection within one second. This is because the standard cron daemon only has a granularity of one minute. In this article, I am going to quickly elaborate on how we
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Continue Reading “Systems Administrator’s Lab: OpenSSH MaxStartups”
Amazon EC2 & Rackspace Cloud Servers
Background Recently, I had the chance to work on a couple of projects that took me into the cloud. The first project had me setting up Eucalyptus on KVM. The second had me building out an infrastructure in Rackspace Cloud Servers. This has given me some hands on insight into the problems that are facing
OpenSSH and Keychain for Systems Administrators
This tutorial provides guidance on best practices and configuration of OpenSSH/Keychain, but also includes some important troubleshooting techniques for which documentation is somewhat lacking. These techniques took me several years to develop and I have tried to compile them here in one concise post so that others do not have to suffer through the arduous learning process
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System’s Administrator’s Lab: Testing
Today, I got an email from the Fedora package manager, Red, who let me know that there was a problem with Petit. I don’t think he knew it, but it was actually my fault that the whole thing got screwed up, so I felt kind of bad. Well, to make a long story short, when
DevOps Culture: An Ethnography
Background An ethnography is a holistic study of another culture conducted by an anthropologist. During the study, the anthropologist lives among the members of the foreign culture, takes notes, and collects data. From this data, the anthropologist develops theories and tests them cross culturally to determine if the source is genetic/biological in nature or enculturated.
Systems Administrator’s Lab: Cacti Development
Background Today, I finally took the time to update a Cacti Data Query which I wrote a while back. When I took a look at it, I found out that it was never actually working for other people strait out of the box. This data query graphs BGP prefixes, messages received and messages sent. I
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Continue Reading “Systems Administrator’s Lab: Cacti Development”
KVM Virtualization 201
Background In my original post KVM Virtualization 101 and my second post KVM Virtualization 102, I explained some basic commands that are necessary to get on using KVM and some features for tuning KVM. In this article I move on to some of the more advanced problems when converting existing Linux machines from a