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    <title>/home/nkorb</title>
    <link>https://blog.nkorb.gr/</link>
    <description>Recent content on /home/nkorb</description>
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    <copyright>&amp;copy; 2019 Nikos Kormpakis</copyright>
    <lastBuildDate>Fri, 22 Nov 2019 00:00:00 +0000</lastBuildDate>
    
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    <item>
      <title>whoami</title>
      <link>https://blog.nkorb.gr/whoami/</link>
      <pubDate>Fri, 22 Nov 2019 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/whoami/</guid>
      <description>My name is Nikos Kormpakis and I&amp;rsquo;m from Greece, currently living in Athens. If you&amp;rsquo;re curious, my name in Greek is Νίκος Κορμπάκης.
My interests revolve around computing in general, especially infrastructure and complex systems. When not messing around with computers, you will find me shooting with my Nikon D7200, DJing with my Pioneer DDJ SB2, operating my U/V Amateur Radio transceivers as SV1QYH.
I currently work as a Systems Engineer at GRNET, Greece&amp;rsquo;s National Research and Educational Network.</description>
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    <item>
      <title>Μια φωτογραφία απευθείας από το διάστημα</title>
      <link>https://blog.nkorb.gr/blog/2019-09-08-iss-sstv/</link>
      <pubDate>Sun, 08 Sep 2019 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/blog/2019-09-08-iss-sstv/</guid>
      <description>Η πρώτη μου φωτογραφία από το διάστημα :)
  Μια φορά και έναν καιρό κάπου στο διάστημα To 1983, ένας αστροναύτης εν ονόματι Owen Garriott, ετοιμαζόταν για μια αποστολή στο διάστημα στον Skylab, τον πρόγονο του ISS. Η αποστολή περιείχε διάφορα πραγματάκια, όπως παρατήρηση της γης, μερικά επιστημονικά πειράματα, κλπ. Όμως, εκείνη η αποστολή είχε κάτι το διαφορετικό.
Όπως σε κάθε μεγάλο ταξίδι, ο κόσμος παίρνει μαζί του τα αγαπημένα του πράγματα, φωτογραφίες, βιβλία και τα σχετικά.</description>
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    <item>
      <title>VMs available in &gt;5 minutes after upgrading Debian. Why?</title>
      <link>https://blog.nkorb.gr/blog/vms-not-booting/</link>
      <pubDate>Tue, 03 Sep 2019 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/blog/vms-not-booting/</guid>
      <description>At work, we manage a fleet of bare metal servers and virtual machines, running Debian GNU/Linux. Upgrades to a new major are often very challenging; not because of the actual upgrade path, but because of the unwanted side-effects that noone had predicted.
One of these side-effects was: &amp;ldquo;Why this shiny Buster VM takes 5 minutes to boot?&amp;ldquo;. Together with my colleague Alexandros Afentoulis, we figured out the issue, fixed it and wrote a post about it.</description>
    </item>
    
    <item>
      <title>A performance story: How a faulty QSFP crippled a Ceph cluster</title>
      <link>https://blog.nkorb.gr/blog/ceph-qsfp/</link>
      <pubDate>Thu, 30 Aug 2018 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/blog/ceph-qsfp/</guid>
      <description>At work, we encountered a strange case of performance degradation on one of our production Ceph clusters which provides storage to our public cloud ~okeanos.
We wrote a post at our tech blog, explaining the problem, our debugging journey, how we solved it and what we&amp;rsquo;ve done for the future. Long story short, a QSFP in the underlying network infrastructure, introduced huge packet loss and caused performance issues to our cloud.</description>
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    <item>
      <title>Open sourcing GRNET&#39;s Ceph tools</title>
      <link>https://blog.nkorb.gr/blog/grnet-cephtools/</link>
      <pubDate>Wed, 30 May 2018 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/blog/grnet-cephtools/</guid>
      <description>I&amp;rsquo;m not afraid to say that I really like Ceph. It&amp;rsquo;s one of the first distributed systems that I got in touch with and I really enjoy working and providing useful services with it. But as all large and complex systems, it tends to get quickly difficult to perform operations on it. For that reason, my team invested some time and wrote a bunch of useful tools that we use in order to manage our Ceph clusters.</description>
    </item>
    
    <item>
      <title>Discovering iproute2 features (Part I)</title>
      <link>https://blog.nkorb.gr/blog/iproute2-feat-p1/</link>
      <pubDate>Mon, 28 May 2018 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/blog/iproute2-feat-p1/</guid>
      <description>iproute2 is the standard networking toolbox for Linux, deprecating the unmaintained net-tools. iproute2 includes the known ip tool, which most admins and engineers use almost every day in order to see and manipulate a host&amp;rsquo;s network configuration. Today, I&amp;rsquo;m going to present some nice (and sometimes undocumented) features of ip that I was not aware of until lately.
The following commands were all tested on a Debian Stretch box, running iproute2 version 4.</description>
    </item>
    
    <item>
      <title>Creating a Debian package from scratch</title>
      <link>https://blog.nkorb.gr/blog/debian-package-scratch/</link>
      <pubDate>Mon, 21 May 2018 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/blog/debian-package-scratch/</guid>
      <description>At work, we use exclusively Debian across our fleet. We try to keep up with the latest stable distribution, without relying on third-party repositories. Also, we try to package every piece of software we&amp;rsquo;re installing on our boxes, including our IaaS cloud software Synnefo and tools that are not found in upstream Debian repos (i.e. check_mk). So, it is not uncommon that we have to create a Debian deb package from scratch.</description>
    </item>
    
    <item>
      <title>Ceph in the GRNET cloud stack</title>
      <link>https://blog.nkorb.gr/blog/ceph-grnet-presentation/</link>
      <pubDate>Sat, 19 May 2018 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/blog/ceph-grnet-presentation/</guid>
      <description>Before some months, I did a presentation on GRNET&amp;rsquo;s Ceph deployments at the 1st GEANT SIG-CISS meeting. If you&amp;rsquo;re interested on how we run Ceph (or maybe, how we used to run it in September 2017), here are the slides of the presentation:
 </description>
    </item>
    
    <item>
      <title>Hunting a bug in Debian&#39;s cron package (Part I)</title>
      <link>https://blog.nkorb.gr/blog/cron-bug-part-1/</link>
      <pubDate>Sat, 19 May 2018 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/blog/cron-bug-part-1/</guid>
      <description>I started writing this post initially about a bug (is it really a bug?) in Debian&amp;rsquo;s cron implementation (Vixie Cron plus some patches). Along the way, I noticed that a fix for this &amp;ldquo;bug&amp;rdquo; might not be easy&amp;hellip;
One annoying thing when getting emails from cron, is that you somethimes you cannot determine which is the problematic host. At work we use a naming scheme for some hosts which looks like this: $role$number.</description>
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    <item>
      <title>Hello World!</title>
      <link>https://blog.nkorb.gr/blog/welcome/</link>
      <pubDate>Tue, 01 May 2018 00:00:00 +0000</pubDate>
      
      <guid>https://blog.nkorb.gr/blog/welcome/</guid>
      <description>Hello world!
My name is Nikos Kormpakis and this is my first post.
I decided to create this small blog in order to &amp;ldquo;claim&amp;rdquo; my little corner in the cyberspace :). In this blog, I’ll share my opinions and experiences with the stuff I mess around: Computers, music, politics, photography, free software, amateur radio, etc.
I’ll try to write most of the time in English but you may encounter some Greek posts :).</description>
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