<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
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- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
<li><a href="tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="tags/debian edu">debian edu (4)</a></li>
- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
<li><a href="tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="tags/debian edu">debian edu (4)</a></li>
- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
<li><a href="tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
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- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
<li><a href="tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
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<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
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- <li><a href="tags/english">english (4)</a></li>
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<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
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<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
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<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
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<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
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- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
<li><a href="tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="tags/debian edu">debian edu (4)</a></li>
- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
<li><a href="tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="tags/debian edu">debian edu (4)</a></li>
- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
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<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="tags/debian edu">debian edu (4)</a></li>
- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
<li><a href="tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="tags/debian edu">debian edu (4)</a></li>
- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
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<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
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<li><a href="archive/2009/01/">January (8)</a></li>
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<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
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<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
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<li><a href="tags/norsk">norsk (22)</a></li>
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<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
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<li><a href="archive/2009/01/">January (8)</a></li>
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<li><a href="archive/2009/01/">January (8)</a></li>
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<li><a href="archive/2009/01/">January (8)</a></li>
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--- /dev/null
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
+ "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
+<html>
+ <head>
+ <title>Petter Reinholdtsen: Using bar codes at a computing center</title>
+ <link rel="stylesheet" type="text/css" media="screen" href="style.css">
+ </head>
+ <body>
+
+ <div class="title">
+ <h1>
+ <a href="">Petter Reinholdtsen</a>
+
+ </h1>
+
+ </div>
+
+
+ <div class="entry">
+ <div class="title">Using bar codes at a computing center</div>
+ <div class="date">2009-02-20 08:30</div>
+ <div class="body">
+<p>At work with the University of Oslo, we have several hundred computers
+in our computing center. This give us a challenge in tracking the
+location and cabling of the computers, when they are added, moved and
+removed. Some times the location register is not updated when a
+computer is inserted or moved and we then have to search the room for
+the "missing" computer.</p>
+
+<p>In the last issue of Linux Journal, I came across a project
+<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
+code blocks as defined in the
+<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
+Standard</a>. This is bar codes that can be read with a normal
+digital camera, for example that on a cell phone, and several such bar
+codes can be read by libdmtx from one picture. The bar code standard
+allow up to 2 KiB to be written in the tag. There is another project
+with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
+writer written in postscript</a> capable of creating such bar codes,
+but this was the first time I found a tool to read these bar
+codes.</p>
+
+<p>It occurred to me that this could be used to tag and track the
+machines in our computing center. If both racks and computers are
+tagged this way, we can use a picture of the rack and all its
+computers to detect the rack location of any computer in that rack.
+If we do this regularly for the entire room, we will find all
+locations, and can detect movements and removals.</p>
+
+<p>I decided to test if this would work in practice, and picked a
+random rack and tagged all the machines with their names. Next, I
+took pictures with my digital camera, and gave the dmtxread program
+these JPEG pictures to see how many tags it could read. This worked
+fairly well. If the pictures was well focused and not taken from the
+side, all tags in the image could be read. Because of limited space
+between the racks, I was unable to get a good picture of the entire
+rack, but could without problem read all tags from a picture covering
+about half the rack. I had to limit the search time used by dmtxread
+to 60000 ms to make sure it terminated in a reasonable time frame.</p>
+
+<p>My conclusion is that this could work, and we should probably look
+at adjusting our computer tagging procedures to use bar codes for
+easier automatic tracking of computers.</p>
+</div>
+
+ <div class="tags">Tags: <a href="tags/english">english</a>, <a href="tags/nuug">nuug</a>.</div>
+
+ </div>
+
+
+
+
+
+
+<div id="sidebar">
+
+<h2>Archive</h2>
+<ul>
+
+<li>2009
+<ul>
+
+<li><a href="archive/2009/01/">January (8)</a></li>
+
+<li><a href="archive/2009/02/">February (7)</a></li>
+
+</ul></li>
+
+<li>2008
+<ul>
+
+<li><a href="archive/2008/11/">November (5)</a></li>
+
+<li><a href="archive/2008/12/">December (7)</a></li>
+
+</ul></li>
+
+</ul>
+
+
+
+<h2>Tags</h2>
+<ul>
+
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+ <li><a href="tags/personvern">personvern (3)</a></li>
+
+ <li><a href="tags/reprap">reprap (7)</a></li>
+
+ <li><a href="tags/rss">rss (1)</a></li>
+
+ <li><a href="tags/stavekontroll">stavekontroll (1)</a></li>
+
+ <li><a href="tags/video">video (3)</a></li>
+
+ <li><a href="tags/web">web (2)</a></li>
+
+</ul>
+
+</div>
+ </body>
+</html>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="tags/debian edu">debian edu (4)</a></li>
- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
<li><a href="tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<li><a href="../../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../../tags/english">english (4)</a></li>
+ <li><a href="../../../tags/english">english (5)</a></li>
<li><a href="../../../tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="../../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../../tags/nuug">nuug (19)</a></li>
<li><a href="../../../tags/personvern">personvern (3)</a></li>
<li><a href="../../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../../tags/english">english (4)</a></li>
+ <li><a href="../../../tags/english">english (5)</a></li>
<li><a href="../../../tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="../../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../../tags/nuug">nuug (19)</a></li>
<li><a href="../../../tags/personvern">personvern (3)</a></li>
<li><a href="../../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../../tags/english">english (4)</a></li>
+ <li><a href="../../../tags/english">english (5)</a></li>
<li><a href="../../../tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="../../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../../tags/nuug">nuug (19)</a></li>
<li><a href="../../../tags/personvern">personvern (3)</a></li>
</description>
</item>
+ <item>
+ <title>Using bar codes at a computing center</title>
+ <link>../../../Using_bar_codes_at_a_computing_center.html</link>
+ <guid isPermaLink="true">../../../Using_bar_codes_at_a_computing_center.html</guid>
+ <pubDate>Fri, 20 Feb 2009 08:30:00 +0100</pubDate>
+ <description>
+<p>At work with the University of Oslo, we have several hundred computers
+in our computing center. This give us a challenge in tracking the
+location and cabling of the computers, when they are added, moved and
+removed. Some times the location register is not updated when a
+computer is inserted or moved and we then have to search the room for
+the "missing" computer.</p>
+
+<p>In the last issue of Linux Journal, I came across a project
+<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
+code blocks as defined in the
+<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
+Standard</a>. This is bar codes that can be read with a normal
+digital camera, for example that on a cell phone, and several such bar
+codes can be read by libdmtx from one picture. The bar code standard
+allow up to 2 KiB to be written in the tag. There is another project
+with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
+writer written in postscript</a> capable of creating such bar codes,
+but this was the first time I found a tool to read these bar
+codes.</p>
+
+<p>It occurred to me that this could be used to tag and track the
+machines in our computing center. If both racks and computers are
+tagged this way, we can use a picture of the rack and all its
+computers to detect the rack location of any computer in that rack.
+If we do this regularly for the entire room, we will find all
+locations, and can detect movements and removals.</p>
+
+<p>I decided to test if this would work in practice, and picked a
+random rack and tagged all the machines with their names. Next, I
+took pictures with my digital camera, and gave the dmtxread program
+these JPEG pictures to see how many tags it could read. This worked
+fairly well. If the pictures was well focused and not taken from the
+side, all tags in the image could be read. Because of limited space
+between the racks, I was unable to get a good picture of the entire
+rack, but could without problem read all tags from a picture covering
+about half the rack. I had to limit the search time used by dmtxread
+to 60000 ms to make sure it terminated in a reasonable time frame.</p>
+
+<p>My conclusion is that this could work, and we should probably look
+at adjusting our computer tagging procedures to use bar codes for
+easier automatic tracking of computers.</p>
+</description>
+ </item>
+
</channel>
</rss>
</div>
<div class="padding"></div>
+<div class="entry">
+ <div class="title">
+ <a href="../../../Using_bar_codes_at_a_computing_center.html">Using bar codes at a computing center</a>
+ </div>
+ <div class="date">
+ 2009-02-20 08:30
+ </div>
+
+ <div class="body">
+
+<p>At work with the University of Oslo, we have several hundred computers
+in our computing center. This give us a challenge in tracking the
+location and cabling of the computers, when they are added, moved and
+removed. Some times the location register is not updated when a
+computer is inserted or moved and we then have to search the room for
+the "missing" computer.</p>
+
+<p>In the last issue of Linux Journal, I came across a project
+<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
+code blocks as defined in the
+<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
+Standard</a>. This is bar codes that can be read with a normal
+digital camera, for example that on a cell phone, and several such bar
+codes can be read by libdmtx from one picture. The bar code standard
+allow up to 2 KiB to be written in the tag. There is another project
+with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
+writer written in postscript</a> capable of creating such bar codes,
+but this was the first time I found a tool to read these bar
+codes.</p>
+
+<p>It occurred to me that this could be used to tag and track the
+machines in our computing center. If both racks and computers are
+tagged this way, we can use a picture of the rack and all its
+computers to detect the rack location of any computer in that rack.
+If we do this regularly for the entire room, we will find all
+locations, and can detect movements and removals.</p>
+
+<p>I decided to test if this would work in practice, and picked a
+random rack and tagged all the machines with their names. Next, I
+took pictures with my digital camera, and gave the dmtxread program
+these JPEG pictures to see how many tags it could read. This worked
+fairly well. If the pictures was well focused and not taken from the
+side, all tags in the image could be read. Because of limited space
+between the racks, I was unable to get a good picture of the entire
+rack, but could without problem read all tags from a picture covering
+about half the rack. I had to limit the search time used by dmtxread
+to 60000 ms to make sure it terminated in a reasonable time frame.</p>
+
+<p>My conclusion is that this could work, and we should probably look
+at adjusting our computer tagging procedures to use bar codes for
+easier automatic tracking of computers.</p>
+
+ </div>
+ <div class="tags">
+
+
+
+ Tags: <a href="../../../tags/english">english</a>, <a href="../../../tags/nuug">nuug</a>.
+
+ </div>
+</div>
+ <div class="padding"></div>
+
<p style="text-align: right;"><a href="02.rss"><img src="../../../xml.gif" alt="RSS Feed" width="36" height="14"></a></p>
<li><a href="../../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../../tags/english">english (4)</a></li>
+ <li><a href="../../../tags/english">english (5)</a></li>
<li><a href="../../../tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="../../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../../tags/nuug">nuug (19)</a></li>
<li><a href="../../../tags/personvern">personvern (3)</a></li>
+ <div class="entry">
+ <div class="title"><a href="Using_bar_codes_at_a_computing_center.html">Using bar codes at a computing center</a></div>
+ <div class="date">2009-02-20 08:30</div>
+ <div class="body">
+<p>At work with the University of Oslo, we have several hundred computers
+in our computing center. This give us a challenge in tracking the
+location and cabling of the computers, when they are added, moved and
+removed. Some times the location register is not updated when a
+computer is inserted or moved and we then have to search the room for
+the "missing" computer.</p>
+
+<p>In the last issue of Linux Journal, I came across a project
+<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
+code blocks as defined in the
+<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
+Standard</a>. This is bar codes that can be read with a normal
+digital camera, for example that on a cell phone, and several such bar
+codes can be read by libdmtx from one picture. The bar code standard
+allow up to 2 KiB to be written in the tag. There is another project
+with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
+writer written in postscript</a> capable of creating such bar codes,
+but this was the first time I found a tool to read these bar
+codes.</p>
+
+<p>It occurred to me that this could be used to tag and track the
+machines in our computing center. If both racks and computers are
+tagged this way, we can use a picture of the rack and all its
+computers to detect the rack location of any computer in that rack.
+If we do this regularly for the entire room, we will find all
+locations, and can detect movements and removals.</p>
+
+<p>I decided to test if this would work in practice, and picked a
+random rack and tagged all the machines with their names. Next, I
+took pictures with my digital camera, and gave the dmtxread program
+these JPEG pictures to see how many tags it could read. This worked
+fairly well. If the pictures was well focused and not taken from the
+side, all tags in the image could be read. Because of limited space
+between the racks, I was unable to get a good picture of the entire
+rack, but could without problem read all tags from a picture covering
+about half the rack. I had to limit the search time used by dmtxread
+to 60000 ms to make sure it terminated in a reasonable time frame.</p>
+
+<p>My conclusion is that this could work, and we should probably look
+at adjusting our computer tagging procedures to use bar codes for
+easier automatic tracking of computers.</p>
+</div>
+ <div class="tags">
+
+
+
+ Tags: <a href="tags/english">english</a>, <a href="tags/nuug">nuug</a>.
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
<div class="entry">
<div class="title"><a href="Kart_over_overv__kningskamera_i_Norge.html">Kart over overvåkningskamera i Norge</a></div>
<div class="date">2009-02-15 22:30</div>
- Tags: <a href="tags/norsk">norsk</a>, <a href="tags/nuug">nuug</a>.
-
- </div>
- </div>
- <div class="padding"></div>
-
- <div class="entry">
- <div class="title"><a href="Det_vanskelige_Lisensvalget___ikke_lag_din_egen.html">Det vanskelige Lisensvalget - ikke lag din egen</a></div>
- <div class="date">2009-01-22 22:15</div>
- <div class="body">
-<p>Min mormor har intet dypt forhold til opphavsrettsloven. Hun eier
-ingen kopimaskin eller datamaskin. Hun kan ikke bruke videoopptaker,
-og er generelt sjelden i en situasjon der hun kunne tenkes å kopiere
-noe som er opphavsrettslig vernet. Da jeg en gang forklarte at jeg
-var involvert i
-<a href="http://www.openstreetmap.org/">OpenStreetmap-prosjektet</a>
-(hun lurte på hvorfor jeg kjørte rundt i nabolaget med GPS), var
-"hvorfor ikke bruke de offisielle kartene fra kartverket " det første
-hun spurte om. Jeg er usikker på om svaret ga mening, i og med at
-hun aldri har tenkt nøye over bruksrettigheter og slikt. Hva skulle
-hun med retten til videredistribusjon av nye kartkopier, som ikke
-kopierer kart? Hva skulle hun med retten til å publisere endrede
-utgaver som aldri har hatt behov for annet enn å notere litt på en
-kartkopi? Det er altså mulig å gå igjennom livet (og det har vært
-et langt og innholdsrikt liv for min mormor) uten å forholde seg til
-opphavsrettsloven.</p>
-
-<p>Andre igjen trenger solid kunnskap om konsekvensene av paragrafene
-i opphavsrettsloven i sitt daglige virke, men har av ulike årsaker
-ikke satt seg nøye inn i lovens konsekvens. Denne teksten er tiltenkt
-slike lesere.</p>
-
-<p>Når en publiserer programvare eller annet opphavsrettsbeskyttet
-materiale (eller "verk" som loven kaller det), så er det endel ting
-som er lurt å tenke på. Hvis en ikke sier noe spesifikt om vilkårene
-for publiseringen, så er det opphavsrettens grunnregler som gjelder.
-De sier blant annet at ingen andre enn rettighetshaver kan publisere,
-kopiere og endre verket. Hvis en ønsker å publisere noe uten
-bruksbegrensninger for mottaker (f.eks. fri programvare eller fritt
-tilgjengelige data), så må en altså eksplisitt gi tillatelse for andre
-til å gjøre disse tingene. Slike eksplisitte tillatelser kalles
-gjerne lisenser. Det er en god del å tenke på når en lager lisenser,
-og det er enkelt å gjøre feil, slik at lisensen ikke uttrykker
-intensjonen med publiseringen. Det er derfor lurt å gjenbruke en
-eksisterende lisenstekst hvis det er mulig.</p>
-
-<p>Av flere årsaker er det lurt å ikke finne på sin egen lisenstekst.
-For det første gir det jobb for de som ønsker å bruke verket å sette
-seg inn i, forstå og vurdere hver enkelt lisens, for å finne ut om den
-dekker bruksbehovet. Hver ny lisensvariant gir dermed ekstra arbeide
-for de organisasjoner og individer som vurderer å ta i bruk et
-opphavsrettsbeskyttet verk. Gjenbruk forutsetter gjerne bruk sammen
-med andre verk, f.eks. programmer og biblioteker skal settes sammen
-til et hele, eller datafiler skal brukes sammen med programmer. Det
-er fort gjort å lage en hjemmesnekret lisens som ikke tillater bruk
-sammen med andre komponenter hvis en ikke er påpasselig med
-utformingen av lisensen (såkalte inkompatible lisenser), spesielt hvis
-det ikke er intensjonen ved publisering. Og for det andre, så er det
-fort gjort å glemme noe når en lager lisensteksten, slik at
-rettigheter en ønsket å gi til brukerne ikke blir nevnt og lovens
-begresninger gjelder.. <strong>Første regel ved lisensvalg er derfor
-å unngå å lage sin egen, men forsøke så langt som mulig å bruke en av
-de utallige eksisterende lisensene.</strong></p>
-
-<p>Et lite eksempel på problemer som kan oppstå er
-<a href="http://api.met.no/lisens.html">betingelsene som Meteorologisk
-institutt har gjort sine data tilgjengelig under</a>. De ser pr. i
-dag slik ut (kopiert hit for å sikre at framtidige lesere kjenner
-innholdet hvis de endres):</p>
-
-<blockquote><p>Betingelser for bruk av data
-<br/>Meteorologisk institutt innehar immaterielle- og
-eiendomsrettigheter til data og produkter produsert av instituttet
-(heretter omtalt som PRODUKTER/PRODUKTENE). Selv om et utvalg
-PRODUKTER er tilgjengelige her for nedlasting og bruk, medfører ikke
-dette på noen måte overdragelse av disse rettighetene. PRODUKTENE kan
-brukes til ethvert formål som ikke er i strid med norsk lov. Dersom
-PRODUKTENE videreformidles i opprinnelig form eller i en form hvor de
-opprinnelige PRODUKTENE utgjør en vesentlig og/eller en lett
-gjenkjennelig del, skal Meteorologisk institutt oppgies som
-kilde. Dette må gjøres på en godt synlig måte. Meteorologisk institutt
-kan ikke holdes ansvarlig for eventuelle konsekvenser av bruken av
-PRODUKTENE. Meteorologisk institutt garanterer ikke regelmessighet i
-oppdateringen av PRODUKTENE, og endringer i PRODUKTENE kan forekomme
-uten varsel. For direkte leveranse av spesifisert produktsett,
-vennligst kontakt Meteorologisk institutt.</p></blockquote>
-
-<p>Meteorologisk institutt hevder at dette skal gjøre dem "fritt
-tilgjengelige", og det gjør at jeg mistenker at betingelsene ikke
-reflekterer intensjonen bak publiseringen. I lisensen står det ikke
-at en har rett til å endre dataene og publisere det endrede
-resultatet. Det står heller ingenting om hvorvidt en har rett til
-videredistribusjon. Mangelen på tillatelse til slik bruk gjør at jeg
-ikke ville omtale datagrunnlaget som fritt tilgjengelig. Det er i
-strid med kriteriene for Free Software
-<a href="http://www.fsf.org/licensing/essays/free-sw.html">publisert
-av FSF</a>,
-<a href="http://www.debian.org/social_contract#guidelines">Debian Free
-Software Guidelines</a> og NUUGs beskrivelse av fri programvare
-publisert i
-<a href="http://www.nuug.no/dokumenter/folder-friprogramvare.pdf">NUUGs
-folder om dette</a>. Jeg lurer på hvorfor Meteorologisk institutt
-ikke valgte noen kjent lisens? Skulle tro at en Creative
-Commons-lisens eller en av de mest brukte fri programvarelisensene som
-GPL og BSD kunne duge. Jeg håper Meteorologisk institutt revurderer
-og endrer på betingelsene.</p>
-</div>
- <div class="tags">
-
-
-
Tags: <a href="tags/norsk">norsk</a>, <a href="tags/nuug">nuug</a>.
</div>
<li><a href="archive/2009/01/">January (8)</a></li>
-<li><a href="archive/2009/02/">February (6)</a></li>
+<li><a href="archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="tags/debian edu">debian edu (4)</a></li>
- <li><a href="tags/english">english (4)</a></li>
+ <li><a href="tags/english">english (5)</a></li>
<li><a href="tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="tags/norsk">norsk (22)</a></li>
- <li><a href="tags/nuug">nuug (18)</a></li>
+ <li><a href="tags/nuug">nuug (19)</a></li>
<li><a href="tags/personvern">personvern (3)</a></li>
<link></link>
<atom:link href="index.rss" rel="self" type="application/rss+xml" />
+ <item>
+ <title>Using bar codes at a computing center</title>
+ <link>Using_bar_codes_at_a_computing_center.html</link>
+ <guid isPermaLink="true">Using_bar_codes_at_a_computing_center.html</guid>
+ <pubDate>Fri, 20 Feb 2009 08:30:00 +0100</pubDate>
+ <description>
+<p>At work with the University of Oslo, we have several hundred computers
+in our computing center. This give us a challenge in tracking the
+location and cabling of the computers, when they are added, moved and
+removed. Some times the location register is not updated when a
+computer is inserted or moved and we then have to search the room for
+the "missing" computer.</p>
+
+<p>In the last issue of Linux Journal, I came across a project
+<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
+code blocks as defined in the
+<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
+Standard</a>. This is bar codes that can be read with a normal
+digital camera, for example that on a cell phone, and several such bar
+codes can be read by libdmtx from one picture. The bar code standard
+allow up to 2 KiB to be written in the tag. There is another project
+with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
+writer written in postscript</a> capable of creating such bar codes,
+but this was the first time I found a tool to read these bar
+codes.</p>
+
+<p>It occurred to me that this could be used to tag and track the
+machines in our computing center. If both racks and computers are
+tagged this way, we can use a picture of the rack and all its
+computers to detect the rack location of any computer in that rack.
+If we do this regularly for the entire room, we will find all
+locations, and can detect movements and removals.</p>
+
+<p>I decided to test if this would work in practice, and picked a
+random rack and tagged all the machines with their names. Next, I
+took pictures with my digital camera, and gave the dmtxread program
+these JPEG pictures to see how many tags it could read. This worked
+fairly well. If the pictures was well focused and not taken from the
+side, all tags in the image could be read. Because of limited space
+between the racks, I was unable to get a good picture of the entire
+rack, but could without problem read all tags from a picture covering
+about half the rack. I had to limit the search time used by dmtxread
+to 60000 ms to make sure it terminated in a reasonable time frame.</p>
+
+<p>My conclusion is that this could work, and we should probably look
+at adjusting our computer tagging procedures to use bar codes for
+easier automatic tracking of computers.</p>
+</description>
+ </item>
+
<item>
<title>Kart over overvåkningskamera i Norge</title>
<link>Kart_over_overv__kningskamera_i_Norge.html</link>
</description>
</item>
- <item>
- <title>Det vanskelige Lisensvalget - ikke lag din egen</title>
- <link>Det_vanskelige_Lisensvalget___ikke_lag_din_egen.html</link>
- <guid isPermaLink="true">Det_vanskelige_Lisensvalget___ikke_lag_din_egen.html</guid>
- <pubDate>Thu, 22 Jan 2009 22:15:00 +0100</pubDate>
- <description>
-<p>Min mormor har intet dypt forhold til opphavsrettsloven. Hun eier
-ingen kopimaskin eller datamaskin. Hun kan ikke bruke videoopptaker,
-og er generelt sjelden i en situasjon der hun kunne tenkes å kopiere
-noe som er opphavsrettslig vernet. Da jeg en gang forklarte at jeg
-var involvert i
-<a href="http://www.openstreetmap.org/">OpenStreetmap-prosjektet</a>
-(hun lurte på hvorfor jeg kjørte rundt i nabolaget med GPS), var
-"hvorfor ikke bruke de offisielle kartene fra kartverket " det første
-hun spurte om. Jeg er usikker på om svaret ga mening, i og med at
-hun aldri har tenkt nøye over bruksrettigheter og slikt. Hva skulle
-hun med retten til videredistribusjon av nye kartkopier, som ikke
-kopierer kart? Hva skulle hun med retten til å publisere endrede
-utgaver som aldri har hatt behov for annet enn å notere litt på en
-kartkopi? Det er altså mulig å gå igjennom livet (og det har vært
-et langt og innholdsrikt liv for min mormor) uten å forholde seg til
-opphavsrettsloven.</p>
-
-<p>Andre igjen trenger solid kunnskap om konsekvensene av paragrafene
-i opphavsrettsloven i sitt daglige virke, men har av ulike årsaker
-ikke satt seg nøye inn i lovens konsekvens. Denne teksten er tiltenkt
-slike lesere.</p>
-
-<p>Når en publiserer programvare eller annet opphavsrettsbeskyttet
-materiale (eller "verk" som loven kaller det), så er det endel ting
-som er lurt å tenke på. Hvis en ikke sier noe spesifikt om vilkårene
-for publiseringen, så er det opphavsrettens grunnregler som gjelder.
-De sier blant annet at ingen andre enn rettighetshaver kan publisere,
-kopiere og endre verket. Hvis en ønsker å publisere noe uten
-bruksbegrensninger for mottaker (f.eks. fri programvare eller fritt
-tilgjengelige data), så må en altså eksplisitt gi tillatelse for andre
-til å gjøre disse tingene. Slike eksplisitte tillatelser kalles
-gjerne lisenser. Det er en god del å tenke på når en lager lisenser,
-og det er enkelt å gjøre feil, slik at lisensen ikke uttrykker
-intensjonen med publiseringen. Det er derfor lurt å gjenbruke en
-eksisterende lisenstekst hvis det er mulig.</p>
-
-<p>Av flere årsaker er det lurt å ikke finne på sin egen lisenstekst.
-For det første gir det jobb for de som ønsker å bruke verket å sette
-seg inn i, forstå og vurdere hver enkelt lisens, for å finne ut om den
-dekker bruksbehovet. Hver ny lisensvariant gir dermed ekstra arbeide
-for de organisasjoner og individer som vurderer å ta i bruk et
-opphavsrettsbeskyttet verk. Gjenbruk forutsetter gjerne bruk sammen
-med andre verk, f.eks. programmer og biblioteker skal settes sammen
-til et hele, eller datafiler skal brukes sammen med programmer. Det
-er fort gjort å lage en hjemmesnekret lisens som ikke tillater bruk
-sammen med andre komponenter hvis en ikke er påpasselig med
-utformingen av lisensen (såkalte inkompatible lisenser), spesielt hvis
-det ikke er intensjonen ved publisering. Og for det andre, så er det
-fort gjort å glemme noe når en lager lisensteksten, slik at
-rettigheter en ønsket å gi til brukerne ikke blir nevnt og lovens
-begresninger gjelder.. <strong>Første regel ved lisensvalg er derfor
-å unngå å lage sin egen, men forsøke så langt som mulig å bruke en av
-de utallige eksisterende lisensene.</strong></p>
-
-<p>Et lite eksempel på problemer som kan oppstå er
-<a href="http://api.met.no/lisens.html">betingelsene som Meteorologisk
-institutt har gjort sine data tilgjengelig under</a>. De ser pr. i
-dag slik ut (kopiert hit for å sikre at framtidige lesere kjenner
-innholdet hvis de endres):</p>
-
-<blockquote><p>Betingelser for bruk av data
-<br/>Meteorologisk institutt innehar immaterielle- og
-eiendomsrettigheter til data og produkter produsert av instituttet
-(heretter omtalt som PRODUKTER/PRODUKTENE). Selv om et utvalg
-PRODUKTER er tilgjengelige her for nedlasting og bruk, medfører ikke
-dette på noen måte overdragelse av disse rettighetene. PRODUKTENE kan
-brukes til ethvert formål som ikke er i strid med norsk lov. Dersom
-PRODUKTENE videreformidles i opprinnelig form eller i en form hvor de
-opprinnelige PRODUKTENE utgjør en vesentlig og/eller en lett
-gjenkjennelig del, skal Meteorologisk institutt oppgies som
-kilde. Dette må gjøres på en godt synlig måte. Meteorologisk institutt
-kan ikke holdes ansvarlig for eventuelle konsekvenser av bruken av
-PRODUKTENE. Meteorologisk institutt garanterer ikke regelmessighet i
-oppdateringen av PRODUKTENE, og endringer i PRODUKTENE kan forekomme
-uten varsel. For direkte leveranse av spesifisert produktsett,
-vennligst kontakt Meteorologisk institutt.</p></blockquote>
-
-<p>Meteorologisk institutt hevder at dette skal gjøre dem "fritt
-tilgjengelige", og det gjør at jeg mistenker at betingelsene ikke
-reflekterer intensjonen bak publiseringen. I lisensen står det ikke
-at en har rett til å endre dataene og publisere det endrede
-resultatet. Det står heller ingenting om hvorvidt en har rett til
-videredistribusjon. Mangelen på tillatelse til slik bruk gjør at jeg
-ikke ville omtale datagrunnlaget som fritt tilgjengelig. Det er i
-strid med kriteriene for Free Software
-<a href="http://www.fsf.org/licensing/essays/free-sw.html">publisert
-av FSF</a>,
-<a href="http://www.debian.org/social_contract#guidelines">Debian Free
-Software Guidelines</a> og NUUGs beskrivelse av fri programvare
-publisert i
-<a href="http://www.nuug.no/dokumenter/folder-friprogramvare.pdf">NUUGs
-folder om dette</a>. Jeg lurer på hvorfor Meteorologisk institutt
-ikke valgte noen kjent lisens? Skulle tro at en Creative
-Commons-lisens eller en av de mest brukte fri programvarelisensene som
-GPL og BSD kunne duge. Jeg håper Meteorologisk institutt revurderer
-og endrer på betingelsene.</p>
-</description>
- </item>
-
</channel>
</rss>
<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
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- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
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+ <li><a href="../../tags/nuug">nuug (19)</a></li>
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<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
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- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
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<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
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- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
<li><a href="../../tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../tags/nuug">nuug (19)</a></li>
<li><a href="../../tags/personvern">personvern (3)</a></li>
<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
<li><a href="../../tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../tags/nuug">nuug (19)</a></li>
<li><a href="../../tags/personvern">personvern (3)</a></li>
<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
<li><a href="../../tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../tags/nuug">nuug (19)</a></li>
<li><a href="../../tags/personvern">personvern (3)</a></li>
</description>
</item>
+ <item>
+ <title>Using bar codes at a computing center</title>
+ <link>../../Using_bar_codes_at_a_computing_center.html</link>
+ <guid isPermaLink="true">../../Using_bar_codes_at_a_computing_center.html</guid>
+ <pubDate>Fri, 20 Feb 2009 08:30:00 +0100</pubDate>
+ <description>
+<p>At work with the University of Oslo, we have several hundred computers
+in our computing center. This give us a challenge in tracking the
+location and cabling of the computers, when they are added, moved and
+removed. Some times the location register is not updated when a
+computer is inserted or moved and we then have to search the room for
+the "missing" computer.</p>
+
+<p>In the last issue of Linux Journal, I came across a project
+<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
+code blocks as defined in the
+<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
+Standard</a>. This is bar codes that can be read with a normal
+digital camera, for example that on a cell phone, and several such bar
+codes can be read by libdmtx from one picture. The bar code standard
+allow up to 2 KiB to be written in the tag. There is another project
+with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
+writer written in postscript</a> capable of creating such bar codes,
+but this was the first time I found a tool to read these bar
+codes.</p>
+
+<p>It occurred to me that this could be used to tag and track the
+machines in our computing center. If both racks and computers are
+tagged this way, we can use a picture of the rack and all its
+computers to detect the rack location of any computer in that rack.
+If we do this regularly for the entire room, we will find all
+locations, and can detect movements and removals.</p>
+
+<p>I decided to test if this would work in practice, and picked a
+random rack and tagged all the machines with their names. Next, I
+took pictures with my digital camera, and gave the dmtxread program
+these JPEG pictures to see how many tags it could read. This worked
+fairly well. If the pictures was well focused and not taken from the
+side, all tags in the image could be read. Because of limited space
+between the racks, I was unable to get a good picture of the entire
+rack, but could without problem read all tags from a picture covering
+about half the rack. I had to limit the search time used by dmtxread
+to 60000 ms to make sure it terminated in a reasonable time frame.</p>
+
+<p>My conclusion is that this could work, and we should probably look
+at adjusting our computer tagging procedures to use bar codes for
+easier automatic tracking of computers.</p>
+</description>
+ </item>
+
</channel>
</rss>
</div>
</div>
+<div class="padding"></div>
+
+<div class="entry">
+ <div class="title">
+ <a href="../../Using_bar_codes_at_a_computing_center.html">Using bar codes at a computing center</a>
+ </div>
+ <div class="date">
+ 2009-02-20 08:30
+ </div>
+
+ <div class="body">
+
+<p>At work with the University of Oslo, we have several hundred computers
+in our computing center. This give us a challenge in tracking the
+location and cabling of the computers, when they are added, moved and
+removed. Some times the location register is not updated when a
+computer is inserted or moved and we then have to search the room for
+the "missing" computer.</p>
+
+<p>In the last issue of Linux Journal, I came across a project
+<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
+code blocks as defined in the
+<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
+Standard</a>. This is bar codes that can be read with a normal
+digital camera, for example that on a cell phone, and several such bar
+codes can be read by libdmtx from one picture. The bar code standard
+allow up to 2 KiB to be written in the tag. There is another project
+with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
+writer written in postscript</a> capable of creating such bar codes,
+but this was the first time I found a tool to read these bar
+codes.</p>
+
+<p>It occurred to me that this could be used to tag and track the
+machines in our computing center. If both racks and computers are
+tagged this way, we can use a picture of the rack and all its
+computers to detect the rack location of any computer in that rack.
+If we do this regularly for the entire room, we will find all
+locations, and can detect movements and removals.</p>
+
+<p>I decided to test if this would work in practice, and picked a
+random rack and tagged all the machines with their names. Next, I
+took pictures with my digital camera, and gave the dmtxread program
+these JPEG pictures to see how many tags it could read. This worked
+fairly well. If the pictures was well focused and not taken from the
+side, all tags in the image could be read. Because of limited space
+between the racks, I was unable to get a good picture of the entire
+rack, but could without problem read all tags from a picture covering
+about half the rack. I had to limit the search time used by dmtxread
+to 60000 ms to make sure it terminated in a reasonable time frame.</p>
+
+<p>My conclusion is that this could work, and we should probably look
+at adjusting our computer tagging procedures to use bar codes for
+easier automatic tracking of computers.</p>
+
+ </div>
+ <div class="tags">
+
+
+
+ Tags: <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>.
+
+ </div>
+</div>
<div class="padding"></div>
<p style="text-align: right;"><a href="english.rss"><img src="../../xml.gif" alt="RSS Feed" width="36" height="14"></a></p>
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+ <li><a href="../../tags/nuug">nuug (19)</a></li>
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<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
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- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
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+ <li><a href="../../tags/nuug">nuug (19)</a></li>
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<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
<li><a href="../../tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../tags/nuug">nuug (19)</a></li>
<li><a href="../../tags/personvern">personvern (3)</a></li>
</div>
</div>
+<div class="padding"></div>
+
+<div class="entry">
+ <div class="title">
+ <a href="../../Using_bar_codes_at_a_computing_center.html">Using bar codes at a computing center</a>
+ </div>
+ <div class="date">
+ 2009-02-20 08:30
+ </div>
+
+ <div class="body">
+
+<p>At work with the University of Oslo, we have several hundred computers
+in our computing center. This give us a challenge in tracking the
+location and cabling of the computers, when they are added, moved and
+removed. Some times the location register is not updated when a
+computer is inserted or moved and we then have to search the room for
+the "missing" computer.</p>
+
+<p>In the last issue of Linux Journal, I came across a project
+<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
+code blocks as defined in the
+<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
+Standard</a>. This is bar codes that can be read with a normal
+digital camera, for example that on a cell phone, and several such bar
+codes can be read by libdmtx from one picture. The bar code standard
+allow up to 2 KiB to be written in the tag. There is another project
+with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
+writer written in postscript</a> capable of creating such bar codes,
+but this was the first time I found a tool to read these bar
+codes.</p>
+
+<p>It occurred to me that this could be used to tag and track the
+machines in our computing center. If both racks and computers are
+tagged this way, we can use a picture of the rack and all its
+computers to detect the rack location of any computer in that rack.
+If we do this regularly for the entire room, we will find all
+locations, and can detect movements and removals.</p>
+
+<p>I decided to test if this would work in practice, and picked a
+random rack and tagged all the machines with their names. Next, I
+took pictures with my digital camera, and gave the dmtxread program
+these JPEG pictures to see how many tags it could read. This worked
+fairly well. If the pictures was well focused and not taken from the
+side, all tags in the image could be read. Because of limited space
+between the racks, I was unable to get a good picture of the entire
+rack, but could without problem read all tags from a picture covering
+about half the rack. I had to limit the search time used by dmtxread
+to 60000 ms to make sure it terminated in a reasonable time frame.</p>
+
+<p>My conclusion is that this could work, and we should probably look
+at adjusting our computer tagging procedures to use bar codes for
+easier automatic tracking of computers.</p>
+
+ </div>
+ <div class="tags">
+
+
+
+ Tags: <a href="../../tags/english">english</a>, <a href="../../tags/nuug">nuug</a>.
+
+ </div>
+</div>
<div class="padding"></div>
<p style="text-align: right;"><a href="nuug.rss"><img src="../../xml.gif" alt="RSS Feed" width="36" height="14"></a></p>
<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
<li><a href="../../tags/fiksgatami">fiksgatami (1)</a></li>
<li><a href="../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../tags/nuug">nuug (19)</a></li>
<li><a href="../../tags/personvern">personvern (3)</a></li>
</description>
</item>
+ <item>
+ <title>Using bar codes at a computing center</title>
+ <link>../../Using_bar_codes_at_a_computing_center.html</link>
+ <guid isPermaLink="true">../../Using_bar_codes_at_a_computing_center.html</guid>
+ <pubDate>Fri, 20 Feb 2009 08:30:00 +0100</pubDate>
+ <description>
+<p>At work with the University of Oslo, we have several hundred computers
+in our computing center. This give us a challenge in tracking the
+location and cabling of the computers, when they are added, moved and
+removed. Some times the location register is not updated when a
+computer is inserted or moved and we then have to search the room for
+the "missing" computer.</p>
+
+<p>In the last issue of Linux Journal, I came across a project
+<a href="http://www.libdmtx.org/">libdmtx</a> to write and read bar
+code blocks as defined in the
+<a href="http://en.wikipedia.org/wiki/Data_Matrix">The Data Matrix
+Standard</a>. This is bar codes that can be read with a normal
+digital camera, for example that on a cell phone, and several such bar
+codes can be read by libdmtx from one picture. The bar code standard
+allow up to 2 KiB to be written in the tag. There is another project
+with <a href="http://www.terryburton.co.uk/barcodewriter/">a bar code
+writer written in postscript</a> capable of creating such bar codes,
+but this was the first time I found a tool to read these bar
+codes.</p>
+
+<p>It occurred to me that this could be used to tag and track the
+machines in our computing center. If both racks and computers are
+tagged this way, we can use a picture of the rack and all its
+computers to detect the rack location of any computer in that rack.
+If we do this regularly for the entire room, we will find all
+locations, and can detect movements and removals.</p>
+
+<p>I decided to test if this would work in practice, and picked a
+random rack and tagged all the machines with their names. Next, I
+took pictures with my digital camera, and gave the dmtxread program
+these JPEG pictures to see how many tags it could read. This worked
+fairly well. If the pictures was well focused and not taken from the
+side, all tags in the image could be read. Because of limited space
+between the racks, I was unable to get a good picture of the entire
+rack, but could without problem read all tags from a picture covering
+about half the rack. I had to limit the search time used by dmtxread
+to 60000 ms to make sure it terminated in a reasonable time frame.</p>
+
+<p>My conclusion is that this could work, and we should probably look
+at adjusting our computer tagging procedures to use bar codes for
+easier automatic tracking of computers.</p>
+</description>
+ </item>
+
</channel>
</rss>
<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
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<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../tags/english">english (4)</a></li>
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<li><a href="../../tags/norsk">norsk (22)</a></li>
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+ <li><a href="../../tags/nuug">nuug (19)</a></li>
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<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
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- <li><a href="../../tags/english">english (4)</a></li>
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<li><a href="../../tags/norsk">norsk (22)</a></li>
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+ <li><a href="../../tags/nuug">nuug (19)</a></li>
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<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../tags/english">english (4)</a></li>
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+ <li><a href="../../tags/nuug">nuug (19)</a></li>
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<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
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<li><a href="../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../tags/nuug">nuug (19)</a></li>
<li><a href="../../tags/personvern">personvern (3)</a></li>
<li><a href="../../archive/2009/01/">January (8)</a></li>
-<li><a href="../../archive/2009/02/">February (6)</a></li>
+<li><a href="../../archive/2009/02/">February (7)</a></li>
</ul></li>
<li><a href="../../tags/debian edu">debian edu (4)</a></li>
- <li><a href="../../tags/english">english (4)</a></li>
+ <li><a href="../../tags/english">english (5)</a></li>
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<li><a href="../../tags/norsk">norsk (22)</a></li>
- <li><a href="../../tags/nuug">nuug (18)</a></li>
+ <li><a href="../../tags/nuug">nuug (19)</a></li>
<li><a href="../../tags/personvern">personvern (3)</a></li>
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