Install VirtualBox guest additions on CentOS 7

I am starting with CentOS 7 minimal install, but the steps should work wherever you are starting. In The Host OS First you need to find the Virtual box guest additions iso.  It’s harder to find than it should be. In the host OS (not in the CentOS VM) go to and navigate to your… Read More »

How does a Fyrite work

A fyrite is a volumetric gas analysis device.  The device is used to measure the concentration of a selected gas in a sample of gas.  The gas is “selected” by choosing the composition of the liquid inside the analyzer. I will default to writing about CO2 fyrite The analyzer looks like this (this one is… Read More »

Why you need HTTPS for your web site

The TL;DR: You should not run a website that requires a login without enabling HTTPS on that web site and forcing the use of HTTPS for, at the very least, the login and administration pages. Logging in without HTTPS may allow somebody to steal your password and hack your web site. You should arrange to get… Read More »

How To Set Up VLANs When You Don’t Understand VLANs

Several years ago, I needed to partition a network into separate VLANs.  The switches I had were capable, but I wasn’t.  I was having trouble understanding what the terms meant (Tagged, Untagged, Excluded) and how to configure each port to achieve my desired result.  I had trouble finding a good I-don’t-really-care-that-much-about-VLANS-or-Cisco-documentation-I-just-want-this-to-work-so-I-can-get-on-with-what-I-am-really-trying-to-do kind of explanation, so… Read More »

Gentoo emerge Doesn’t Do Anything!

After performing maintenance on my gentoo linux system, emerge no longer did anything.  Any emerge command would immediately return with no output or result.  This happened to be just after I had run revdep-rebuild.  Revdep-rebuild removed python 2.6 which I didn’t think was a problem because I had just updated python and 2.6 is an… Read More »