Category Archives: CentOS

Your AWS Instance was scheduled for retirement? don’t panic

Intro After nearly four years of continuously running my AWS instance I got this scary email: What to do? The details Since I never dveloped much AWS expertise (never needed to since it just worked) I was afraid to do … Continue reading

Posted in CentOS, Hosting Service | Tagged | 2 Comments

Adding a swap file in Amazon AWS for CentOS

Intro I was running a new daemon on my server, factomd, to experiment with digital currency. It’s an old m1.small instance with only 1.7 GB of memory. The first few times I ran it it would 70000 or so blocks, … Continue reading

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Roll your own dynamic DNS update service

Intro I know my old Cisco router only has built-in support for two dynamic DNS services, dyndns.org and TZO.com. Nowadays you have to pay for those, if even they work (the web site domain names seem to have changed, but … Continue reading

Posted in CentOS, DNS, Linux, Network Technologies, Raspberry Pi, Security, Web Site Technologies | Tagged , , , | Leave a comment

Powershell winrm client error explained

Intro This particular Powershell error I came across yesterday is not well explained in other forums. I present the error and the explanation though not necessarily the solution. The details I recently received my new PC running Windows 8.1. On … Continue reading

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Idea for free web server certificates: Let’s Encrypt

Intro I’ve written various articles about SSL. I just came across a way to get your certificates for free, letsencrypt.org. But their thing is to automate certificate management. I think you have to set up the whole automated certificate management … Continue reading

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The IT Detective Agency: WordPress login failure leads to discovery of ssh brute force attack

Intro Yes my WordPress instance never gave any problems for years. Then one day my usual username/password wouldn’t log me in! One thing led to another until I realized I was under an ssh brute force attack from Hong Kong. … Continue reading

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Compiling Apache 2.4 on CentOS

Intro This is a tale of one thing leading to another. I’ll probably either continue this post or delete it altogether if I find I’m headed down a wrong path. The details I suspect that to get better marks for … Continue reading

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drjohnstechtalk.com is now an encrypted web site

Intro I don’t overtly chase search engine rankings. I’m comfortable being the 2,000,000th most visited site on the Internet, or something like that according to alexa. But I still take pride in what I’m producing here. So when I read … Continue reading

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CentOS 6.0 VM ran out of memory

Intro I’m just creating this post to have documented what happened to me personally. I have a CentOS 6.0 image with Amazon AWS. It was based on a minimal image, which I purposefully selected so it wouldn’t be loaded down … Continue reading

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Example using iptables, the CentOS firewall

Intro This document is mostly for my own purposes. I don’t even think this is the best way to run the firewall, it’s just the way I happened to adapt. Background My friends tell me ipchains was good software. Unfortunately … Continue reading

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