+ <div class="entry">
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Some_notes_on_fault_tolerant_storage_systems.html">Some notes on fault tolerant storage systems</a></div>
+ <div class="date"> 1st November 2017</div>
+ <div class="body"><p>If you care about how fault tolerant your storage is, you might
+find these articles and papers interesting. They have formed how I
+think of when designing a storage system.</p>
+
+<ul>
+
+<li>USENIX :login; <a
+href="https://www.usenix.org/publications/login/summer2017/ganesan">Redundancy
+Does Not Imply Fault Tolerance. Analysis of Distributed Storage
+Reactions to Single Errors and Corruptions</a> by Aishwarya Ganesan,
+Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, and Remzi
+H. Arpaci-Dusseau</li>
+
+<li>ZDNet
+<a href="http://www.zdnet.com/article/why-raid-5-stops-working-in-2009/">Why
+RAID 5 stops working in 2009</a> by Robin Harris</li>
+
+<li>ZDNet
+<a href="http://www.zdnet.com/article/why-raid-6-stops-working-in-2019/">Why
+RAID 6 stops working in 2019</a> by Robin Harris</li>
+
+<li>USENIX FAST'07
+<a href="http://research.google.com/archive/disk_failures.pdf">Failure
+Trends in a Large Disk Drive Population</a> by Eduardo Pinheiro,
+Wolf-Dietrich Weber and Luiz André Barroso</li>
+
+<li>USENIX ;login: <a
+href="https://www.usenix.org/system/files/login/articles/hughes12-04.pdf">Data
+Integrity. Finding Truth in a World of Guesses and Lies</a> by Doug
+Hughes</li>
+
+<li>USENIX FAST'08
+<a href="https://www.usenix.org/events/fast08/tech/full_papers/bairavasundaram/bairavasundaram_html/">An
+cAnalysis of Data Corruption in the Storage Stack</a> by
+L. N. Bairavasundaram, G. R. Goodson, B. Schroeder, A. C.
+Arpaci-Dusseau, and R. H. Arpaci-Dusseau</li>
+
+<li>USENIX FAST'07 <a
+href="https://www.usenix.org/legacy/events/fast07/tech/schroeder/schroeder_html/">Disk
+failures in the real world: what does an MTTF of 1,000,000 hours mean
+to you?</a> by B. Schroeder and G. A. Gibson.</li>
+
+<li>USENIX ;login: <a
+href="https://www.usenix.org/events/fast08/tech/full_papers/jiang/jiang_html/">Are
+Disks the Dominant Contributor for Storage Failures? A Comprehensive
+Study of Storage Subsystem Failure Characteristics</a> by Weihang
+Jiang, Chongfeng Hu, Yuanyuan Zhou, and Arkady Kanevsky</li>
+
+<li>SIGMETRICS 2007
+<a href="http://research.cs.wisc.edu/adsl/Publications/latent-sigmetrics07.pdf">An
+analysis of latent sector errors in disk drives</a> by
+L. N. Bairavasundaram, G. R. Goodson, S. Pasupathy, and J. Schindler</li>
+
+</ul>
+
+<p>Several of these research papers are based on data collected from
+hundred thousands or millions of disk, and their findings are eye
+opening. The short story is simply do not implicitly trust RAID or
+redundant storage systems. Details matter. And unfortunately there
+are few options on Linux addressing all the identified issues. Both
+ZFS and Btrfs are doing a fairly good job, but have legal and
+practical issues on their own. I wonder how cluster file systems like
+Ceph do in this regard. After, all the old saying, you know you have
+a distributed system when the crash of a compyter you have never heard
+of stops you from getting any work done. The same holds true if fault
+tolerance do not work.</p>
+
+<p>Just remember, in the end, it do not matter how redundant, or how
+fault tolerant your storage is, if you do not continuously monitor its
+status to detect and replace failed disks.</p>
+</div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>, <a href="http://people.skolelinux.org/pere/blog/tags/raid">raid</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
+ <div class="entry">
+ <div class="title"><a href="http://people.skolelinux.org/pere/blog/Web_services_for_writing_academic_LaTeX_papers_as_a_team.html">Web services for writing academic LaTeX papers as a team</a></div>
+ <div class="date">31st October 2017</div>
+ <div class="body"><p>I was surprised today to learn that a friend in academia did not
+know there are easily available web services available for writing
+LaTeX documents as a team. I thought it was common knowledge, but to
+make sure at least my readers are aware of it, I would like to mention
+these useful services for writing LaTeX documents. Some of them even
+provide a WYSIWYG editor to ease writing even further.</p>
+
+<p>There are two commercial services available,
+<a href="https://sharelatex.com">ShareLaTeX</a> and
+<a href="https://overleaf.com">Overleaf</a>. They are very easy to
+use. Just start a new document, select which publisher to write for
+(ie which LaTeX style to use), and start writing. Note, these two
+have announced their intention to join forces, so soon it will only be
+one joint service. I've used both for different documents, and they
+work just fine. While
+<a href="https://github.com/sharelatex/sharelatex">ShareLaTeX is free
+software</a>, while the latter is not. According to <a
+href="https://www.overleaf.com/help/17-is-overleaf-open-source">a
+announcement from Overleaf</a>, they plan to keep the ShareLaTeX code
+base maintained as free software.</p>
+
+But these two are not the only alternatives.
+<a href="https://app.fiduswriter.org/">Fidus Writer</a> is another free
+software solution with <a href="https://github.com/fiduswriter">the
+source available on github</a>. I have not used it myself. Several
+others can be found on the nice
+<a href="https://alternativeto.net/software/sharelatex/">alterntiveTo
+web service</a>.
+
+<p>If you like Google Docs or Etherpad, but would like to write
+documents in LaTeX, you should check out these services. You can even
+host your own, if you want to. :)</p>
+
+</div>
+ <div class="tags">
+
+
+ Tags: <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
+
+
+ </div>
+ </div>
+ <div class="padding"></div>
+
<div class="entry">
<div class="title"><a href="http://people.skolelinux.org/pere/blog/Locating_IMDB_IDs_of_movies_in_the_Internet_Archive_using_Wikidata.html">Locating IMDB IDs of movies in the Internet Archive using Wikidata</a></div>
<div class="date">25th October 2017</div>
and check if the XML metadata for the movie is available from The
Internet Archive, and after around 1.5 hour it produced a list of 2097
free movies and their IMDB ID. In total, 171 entries in Wikidata lack
-the refered Internet Archive entry. I assume the 60 "disappearing"
+the refered Internet Archive entry. I assume the 70 "disappearing"
entries (ie 2338-2097-171) are duplicate entries.</p>
<p>This is not too bad, given that The Internet Archive report to
</div>
<div class="padding"></div>
- <div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Norwegian_Bokm_l_edition_of_Debian_Administrator_s_Handbook_is_now_available.html">Norwegian Bokmål edition of Debian Administrator's Handbook is now available</a></div>
- <div class="date">25th July 2017</div>
- <div class="body"><p align="center"><img align="center" src="http://people.skolelinux.org/pere/blog/images/2017-07-25-debian-handbook-nb-testprint.png"/></p>
-
-<p>I finally received a copy of the Norwegian Bokmål edition of
-"<a href="https://debian-handbook.info/">The Debian Administrator's
-Handbook</a>". This test copy arrived in the mail a few days ago, and
-I am very happy to hold the result in my hand. We spent around one and a half year translating it. This paperbook edition
-<a href="https://debian-handbook.info/get/#norwegian">is available
-from lulu.com</a>. If you buy it quickly, you save 25% on the list
-price. The book is also available for download in electronic form as
-PDF, EPUB and Mobipocket, as can be
-<a href="https://debian-handbook.info/browse/nb-NO/stable/">read online
-as a web page</a>.</p>
-
-<p>This is the second book I publish (the first was the book
-"<a href="http://free-culture.cc/">Free Culture</a>" by Lawrence Lessig
-in
-<a href="http://www.lulu.com/shop/lawrence-lessig/free-culture/paperback/product-22440520.html">English</a>,
-<a href="http://www.lulu.com/shop/lawrence-lessig/culture-libre/paperback/product-22645082.html">French</a>
-and
-<a href="http://www.lulu.com/shop/lawrence-lessig/fri-kultur/paperback/product-22441576.html">Norwegian
-Bokmål</a>), and I am very excited to finally wrap up this
-project. I hope
-"<a href="http://www.lulu.com/shop/rapha%C3%ABl-hertzog-and-roland-mas/h%C3%A5ndbok-for-debian-administratoren/paperback/product-23262290.html">Håndbok
-for Debian-administratoren</a>" will be well received.</p>
-</div>
- <div class="tags">
-
-
- Tags: <a href="http://people.skolelinux.org/pere/blog/tags/debian">debian</a>, <a href="http://people.skolelinux.org/pere/blog/tags/debian-handbook">debian-handbook</a>, <a href="http://people.skolelinux.org/pere/blog/tags/english">english</a>.
-
-
- </div>
- </div>
- <div class="padding"></div>
-
- <div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/_Rapporten_ser_ikke_p__informasjonssikkerhet_knyttet_til_personlig_integritet_.html">«Rapporten ser ikke på informasjonssikkerhet knyttet til personlig integritet»</a></div>
- <div class="date">27th June 2017</div>
- <div class="body"><p>Jeg kom over teksten
-«<a href="https://freedom-to-tinker.com/2017/06/21/killing-car-privacy-by-federal-mandate/">Killing
-car privacy by federal mandate</a>» av Leonid Reyzin på Freedom to
-Tinker i dag, og det gleder meg å se en god gjennomgang om hvorfor det
-er et urimelig inngrep i privatsfæren å la alle biler kringkaste sin
-posisjon og bevegelse via radio. Det omtalte forslaget basert på
-Dedicated Short Range Communication (DSRC) kalles Basic Safety Message
-(BSM) i USA og Cooperative Awareness Message (CAM) i Europa, og det
-norske Vegvesenet er en av de som ser ut til å kunne tenke seg å
-pålegge alle biler å fjerne nok en bit av innbyggernes privatsfære.
-Anbefaler alle å lese det som står der.
-
-<p>Mens jeg tittet litt på DSRC på biler i Norge kom jeg over et sitat
-jeg synes er illustrativt for hvordan det offentlige Norge håndterer
-problemstillinger rundt innbyggernes privatsfære i SINTEF-rapporten
-«<a href="https://www.sintef.no/publikasjoner/publikasjon/Download/?pubid=SINTEF+A23933">Informasjonssikkerhet
-i AutoPASS-brikker</a>» av Trond Foss:</p>
-
-<p><blockquote>
-«Rapporten ser ikke på informasjonssikkerhet knyttet til personlig
- integritet.»
-</blockquote></p>
-
-<p>Så enkelt kan det tydeligvis gjøres når en vurderer
-informasjonssikkerheten. Det holder vel at folkene på toppen kan si
-at «Personvernet er ivaretatt», som jo er den populære intetsigende
-frasen som gjør at mange tror enkeltindividers integritet tas vare på.
-Sitatet fikk meg til å undres på hvor ofte samme tilnærming, å bare se
-bort fra behovet for personlig itegritet, blir valgt når en velger å
-legge til rette for nok et inngrep i privatsfæren til personer i
-Norge. Det er jo sjelden det får reaksjoner. Historien om
-reaksjonene på Helse Sør-Østs tjenesteutsetting er jo sørgelig nok et
-unntak og toppen av isfjellet, desverre. Tror jeg fortsatt takker nei
-til både AutoPASS og holder meg så langt unna det norske helsevesenet
-som jeg kan, inntil de har demonstrert og dokumentert at de verdsetter
-individets privatsfære og personlige integritet høyere enn kortsiktig
-gevist og samfunnsnytte.</p>
-</div>
- <div class="tags">
-
-
- Tags: <a href="http://people.skolelinux.org/pere/blog/tags/norsk">norsk</a>, <a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern</a>, <a href="http://people.skolelinux.org/pere/blog/tags/sikkerhet">sikkerhet</a>.
-
-
- </div>
- </div>
- <div class="padding"></div>
-
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<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/09/">September (3)</a></li>
-<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/10/">October (4)</a></li>
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/10/">October (5)</a></li>
+
+<li><a href="http://people.skolelinux.org/pere/blog/archive/2017/11/">November (1)</a></li>
</ul></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/drivstoffpriser">drivstoffpriser (4)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (356)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/english">english (358)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/fiksgatami">fiksgatami (23)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/personvern">personvern (104)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (1)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/raid">raid (2)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/reactos">reactos (1)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/surveillance">surveillance (52)</a></li>
- <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (3)</a></li>
+ <li><a href="http://people.skolelinux.org/pere/blog/tags/sysadmin">sysadmin (4)</a></li>
<li><a href="http://people.skolelinux.org/pere/blog/tags/usenix">usenix (2)</a></li>
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