Jarle's blog

Jarle Bjørgeengen works as senior system engineer at the  IT Operations Framework Group of  USIT. His main responsibilities is development and maintenance of configuration management systems, monitoring and logging systems for Linux and Storage. He finished his masters degree at Oslo University college/University of Oslo  in 2010 .

Published Sep. 9, 2013 12:55 PM

We use graphite for storing time-series. We also use SELinux (in RHEL6) in targeted mode for extra protection of web applications.

It turns out there's a little snag when enabling CLUSTER_SERVERS in the graphite application settings when the web application runs in SELinux enforcing context.

Published July 9, 2013 11:47 AM

Cfengine has powerful and lightweight mechanisms to differentiate applied configuration between different contexts. The mechanism is called context classes, or historically just classes. Classes are used to specify in what particular situation (or context or scope) a particular configuration is relevant.

Cfengine is able to detect  everything about a host and set the appropriate classes based on the discovered context. But what if we want to decide from a central place that a host shall take on certain roles, and let Cfengine apply the «configuration stubs» that implements those roles? This is somewhat different than the classes that the host already «know» about itself. We want to apply additional knowledge to the host making it aware of the roles we think it should fill.

We chose to extend our existing host database to create a structure of machine/host roles and the possibility to tie them to hosts. This extension allows us to apply roles to hosts and have the Cfengine agent detect the roles that we want it to apply to itself.

 

Published Dec. 19, 2012 1:38 PM

During my masters-program  "System and network administration" at OUC i used the opportunity to establish tighter relationship between the masters-program and USIT. Students at OUC visited our data center and several guest lectures were held by USIT staff, introducing architecture, history, processes and organization at USIT. The activities were well received and to the mutual benefits of students and lecturers  at OUC and USIT. 

After finishing the masters degree I've used some time to keep up this relation by holding guest lectures in storage and configuration management, course-planning, and being provider and advisor of master projects.

Here is an overview of these activities: 

Published Dec. 19, 2012 1:38 PM

During the recent and now stalled USIT 2.0 project and in the IHR project the word "quality" and QA (Quality Assurance) occurs frequently. I'm sure everyone agrees that quality is a good thing, and we all aim for high quality in our work every day. But how much thought are  given to the meaning of the word, and what defines quality?