- <div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Detecting_NFS_hangs_on_Linux_without_hanging_yourself___.html">Detecting NFS hangs on Linux without hanging yourself...</a></div>
- <div class="date"> 9th March 2017</div>
- <div class="body"><p>Over the years, administrating thousand of NFS mounting linux
-computers at the time, I often needed a way to detect if the machine
-was experiencing NFS hang. If you try to use <tt>df</tt> or look at a
-file or directory affected by the hang, the process (and possibly the
-shell) will hang too. So you want to be able to detect this without
-risking the detection process getting stuck too. It has not been
-obvious how to do this. When the hang has lasted a while, it is
-possible to find messages like these in dmesg:</p>
-
-<p><blockquote>
-nfs: server nfsserver not responding, still trying
-<br>nfs: server nfsserver OK
-</blockquote></p>
-
-<p>It is hard to know if the hang is still going on, and it is hard to
-be sure looking in dmesg is going to work. If there are lots of other
-messages in dmesg the lines might have rotated out of site before they
-are noticed.</p>
-
-<p>While reading through the nfs client implementation in linux kernel
-code, I came across some statistics that seem to give a way to detect
-it. The om_timeouts sunrpc value in the kernel will increase every
-time the above log entry is inserted into dmesg. And after digging a
-bit further, I discovered that this value show up in
-/proc/self/mountstats on Linux.</p>
-
-<p>The mountstats content seem to be shared between files using the
-same file system context, so it is enough to check one of the
-mountstats files to get the state of the mount point for the machine.
-I assume this will not show lazy umounted NFS points, nor NFS mount
-points in a different process context (ie with a different filesystem
-view), but that does not worry me.</p>
-
-<p>The content for a NFS mount point look similar to this:</p>
-
-<p><blockquote><pre>
-[...]
-device /dev/mapper/Debian-var mounted on /var with fstype ext3
-device nfsserver:/mnt/nfsserver/home0 mounted on /mnt/nfsserver/home0 with fstype nfs statvers=1.1
- opts: rw,vers=3,rsize=65536,wsize=65536,namlen=255,acregmin=3,acregmax=60,acdirmin=30,acdirmax=60,soft,nolock,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=129.240.3.145,mountvers=3,mountport=4048,mountproto=udp,local_lock=all
- age: 7863311
- caps: caps=0x3fe7,wtmult=4096,dtsize=8192,bsize=0,namlen=255
- sec: flavor=1,pseudoflavor=1
- events: 61063112 732346265 1028140 35486205 16220064 8162542 761447191 71714012 37189 3891185 45561809 110486139 4850138 420353 15449177 296502 52736725 13523379 0 52182 9016896 1231 0 0 0 0 0
- bytes: 166253035039 219519120027 0 0 40783504807 185466229638 11677877 45561809
- RPC iostats version: 1.0 p/v: 100003/3 (nfs)
- xprt: tcp 925 1 6810 0 0 111505412 111480497 109 2672418560317 0 248 53869103 22481820
- per-op statistics
- NULL: 0 0 0 0 0 0 0 0
- GETATTR: 61063106 61063108 0 9621383060 6839064400 453650 77291321 78926132
- SETATTR: 463469 463470 0 92005440 66739536 63787 603235 687943
- LOOKUP: 17021657 17021657 0 3354097764 4013442928 57216 35125459 35566511
- ACCESS: 14281703 14290009 5 2318400592 1713803640 1709282 4865144 7130140
- READLINK: 125 125 0 20472 18620 0 1112 1118
- READ: 4214236 4214237 0 715608524 41328653212 89884 22622768 22806693
- WRITE: 8479010 8494376 22 187695798568 1356087148 178264904 51506907 231671771
- CREATE: 171708 171708 0 38084748 46702272 873 1041833 1050398
- MKDIR: 3680 3680 0 773980 993920 26 23990 24245
- SYMLINK: 903 903 0 233428 245488 6 5865 5917
- MKNOD: 80 80 0 20148 21760 0 299 304
- REMOVE: 429921 429921 0 79796004 61908192 3313 2710416 2741636
- RMDIR: 3367 3367 0 645112 484848 22 5782 6002
- RENAME: 466201 466201 0 130026184 121212260 7075 5935207 5961288
- LINK: 289155 289155 0 72775556 67083960 2199 2565060 2585579
- READDIR: 2933237 2933237 0 516506204 13973833412 10385 3190199 3297917
- READDIRPLUS: 1652839 1652839 0 298640972 6895997744 84735 14307895 14448937
- FSSTAT: 6144 6144 0 1010516 1032192 51 9654 10022
- FSINFO: 2 2 0 232 328 0 1 1
- PATHCONF: 1 1 0 116 140 0 0 0
- COMMIT: 0 0 0 0 0 0 0 0
-
-device binfmt_misc mounted on /proc/sys/fs/binfmt_misc with fstype binfmt_misc
-[...]
-</pre></blockquote></p>
-
-<p>The key number to look at is the third number in the per-op list.
-It is the number of NFS timeouts experiences per file system
-operation. Here 22 write timeouts and 5 access timeouts. If these
-numbers are increasing, I believe the machine is experiencing NFS
-hang. Unfortunately the timeout value do not start to increase right
-away. The NFS operations need to time out first, and this can take a
-while. The exact timeout value depend on the setup. For example the
-defaults for TCP and UDP mount points are quite different, and the
-timeout value is affected by the soft, hard, timeo and retrans NFS
-mount options.</p>
-
-<p>The only way I have been able to get working on Debian and RedHat
-Enterprise Linux for getting the timeout count is to peek in /proc/.
-But according to
-<ahref="http://docs.oracle.com/cd/E19253-01/816-4555/netmonitor-12/index.html">Solaris
-10 System Administration Guide: Network Services</a>, the 'nfsstat -c'
-command can be used to get these timeout values. But this do not work
-on Linux, as far as I can tell. I
-<ahref="http://bugs.debian.org/857043">asked Debian about this</a>,
-but have not seen any replies yet.</p>
-
-<p>Is there a better way to figure out if a Linux NFS client is
-experiencing NFS hangs? Is there a way to detect which processes are
-affected? Is there a way to get the NFS mount going quickly once the
-network problem causing the NFS hang has been cleared? I would very
-much welcome some clues, as we regularly run into NFS hangs.</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/english">english</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/How_does_it_feel_to_be_wiretapped__when_you_should_be_doing_the_wiretapping___.html">How does it feel to be wiretapped, when you should be doing the wiretapping...</a></div>
- <div class="date"> 8th March 2017</div>
- <div class="body"><p>So the new president in the United States of America claim to be
-surprised to discover that he was wiretapped during the election
-before he was elected president. He even claim this must be illegal.
-Well, doh, if it is one thing the confirmations from Snowden
-documented, it is that the entire population in USA is wiretapped, one
-way or another. Of course the president candidates were wiretapped,
-alongside the senators, judges and the rest of the people in USA.</p>
-
-<p>Next, the Federal Bureau of Investigation ask the Department of
-Justice to go public rejecting the claims that Donald Trump was
-wiretapped illegally. I fail to see the relevance, given that I am
-sure the surveillance industry in USA believe they have all the legal
-backing they need to conduct mass surveillance on the entire
-world.</p>
-
-<p>There is even the director of the FBI stating that he never saw an
-order requesting wiretapping of Donald Trump. That is not very
-surprising, given how the FISA court work, with all its activity being
-secret. Perhaps he only heard about it?</p>
-
-<p>What I find most sad in this story is how Norwegian journalists
-present it. In a news reports the other day in the radio from the
-Norwegian National broadcasting Company (NRK), I heard the journalist
-claim that 'the FBI denies any wiretapping', while the reality is that
-'the FBI denies any illegal wiretapping'. There is a fundamental and
-important difference, and it make me sad that the journalists are
-unable to grasp it.</p>
-
-<p><strong>Update 2017-03-13:</strong> Look like
-<a href="https://theintercept.com/2017/03/13/rand-paul-is-right-nsa-routinely-monitors-americans-communications-without-warrants/">The
-Intercept report that US Senator Rand Paul confirm what I state above</a>.</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/surveillance">surveillance</a>.
-
-
- </div>
- </div>
- <div class="padding"></div>
-
- <div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Norwegian_Bokm_l_translation_of_The_Debian_Administrator_s_Handbook_complete__proofreading_in_progress.html">Norwegian Bokmål translation of The Debian Administrator's Handbook complete, proofreading in progress</a></div>
- <div class="date"> 3rd March 2017</div>
- <div class="body"><p>For almost a year now, we have been working on making a Norwegian
-Bokmål edition of <a href="https://debian-handbook.info/">The Debian
-Administrator's Handbook</a>. Now, thanks to the tireless effort of
-Ole-Erik, Ingrid and Andreas, the initial translation is complete, and
-we are working on the proof reading to ensure consistent language and
-use of correct computer science terms. The plan is to make the book
-available on paper, as well as in electronic form. For that to
-happen, the proof reading must be completed and all the figures need
-to be translated. If you want to help out, get in touch.</p>
-
-<p><a href="http://people.skolelinux.org/pere/debian-handbook/debian-handbook-nb-NO.pdf">A
-
-fresh PDF edition</a> in A4 format (the final book will have smaller
-pages) of the book created every morning is available for
-proofreading. If you find any errors, please
-<a href="https://hosted.weblate.org/projects/debian-handbook/">visit
-Weblate and correct the error</a>. The
-<a href="http://l.github.io/debian-handbook/stat/nb-NO/index.html">state
-of the translation including figures</a> is a useful source for those
-provide Norwegian bokmål screen shots and figures.</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/Unlimited_randomness_with_the_ChaosKey_.html">Unlimited randomness with the ChaosKey?</a></div>
- <div class="date"> 1st March 2017</div>
- <div class="body"><p>A few days ago I ordered a small batch of
-<a href="http://altusmetrum.org/ChaosKey/">the ChaosKey</a>, a small
-USB dongle for generating entropy created by Bdale Garbee and Keith
-Packard. Yesterday it arrived, and I am very happy to report that it
-work great! According to its designers, to get it to work out of the
-box, you need the Linux kernel version 4.1 or later. I tested on a
-Debian Stretch machine (kernel version 4.9), and there it worked just
-fine, increasing the available entropy very quickly. I wrote a small
-test oneliner to test. It first print the current entropy level,
-drain /dev/random, and then print the entropy level for five seconds.
-Here is the situation without the ChaosKey inserted:</p>
-
-<blockquote><pre>
-% cat /proc/sys/kernel/random/entropy_avail; \
- dd bs=1M if=/dev/random of=/dev/null count=1; \
- for n in $(seq 1 5); do \
- cat /proc/sys/kernel/random/entropy_avail; \
- sleep 1; \
- done
-300
-0+1 oppføringer inn
-0+1 oppføringer ut
-28 byte kopiert, 0,000264565 s, 106 kB/s
-4
-8
-12
-17
-21
-%
-</pre></blockquote>
-
-<p>The entropy level increases by 3-4 every second. In such case any
-application requiring random bits (like a HTTPS enabled web server)
-will halt and wait for more entrpy. And here is the situation with
-the ChaosKey inserted:</p>
-
-<blockquote><pre>
-% cat /proc/sys/kernel/random/entropy_avail; \
- dd bs=1M if=/dev/random of=/dev/null count=1; \
- for n in $(seq 1 5); do \
- cat /proc/sys/kernel/random/entropy_avail; \
- sleep 1; \
- done
-1079
-0+1 oppføringer inn
-0+1 oppføringer ut
-104 byte kopiert, 0,000487647 s, 213 kB/s
-433
-1028
-1031
-1035
-1038
-%
-</pre></blockquote>
-
-<p>Quite the difference. :) I bought a few more than I need, in case
-someone want to buy one here in Norway. :)</p>
-
-<p>Update: The dongle was presented at Debconf last year. You might
-find <a href="https://debconf16.debconf.org/talks/94/">the talk
-recording illuminating</a>. It explains exactly what the source of
-randomness is, if you are unable to spot it from the schema drawing
-available from the ChaosKey web site linked at the start of this blog
-post.</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/english">english</a>.
-
-
- </div>
- </div>
- <div class="padding"></div>
-
- <div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Detect_OOXML_files_with_undefined_behaviour_.html">Detect OOXML files with undefined behaviour?</a></div>
- <div class="date">21st February 2017</div>
- <div class="body"><p>I just noticed
-<a href="http://www.arkivrad.no/aktuelt/riksarkivarens-forskrift-pa-horing">the
-new Norwegian proposal for archiving rules in the goverment</a> list
-<a href="http://www.ecma-international.org/publications/standards/Ecma-376.htm">ECMA-376</a>
-/ ISO/IEC 29500 (aka OOXML) as valid formats to put in long term
-storage. Luckily such files will only be accepted based on
-pre-approval from the National Archive. Allowing OOXML files to be
-used for long term storage might seem like a good idea as long as we
-forget that there are plenty of ways for a "valid" OOXML document to
-have content with no defined interpretation in the standard, which
-lead to a question and an idea.</p>
-
-<p>Is there any tool to detect if a OOXML document depend on such
-undefined behaviour? It would be useful for the National Archive (and
-anyone else interested in verifying that a document is well defined)
-to have such tool available when considering to approve the use of
-OOXML. I'm aware of the
-<a href="https://github.com/arlm/officeotron/">officeotron OOXML
-validator</a>, but do not know how complete it is nor if it will
-report use of undefined behaviour. Are there other similar tools
-available? Please send me an email if you know of any such tool.</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/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/standard">standard</a>.
-
-
- </div>
- </div>
- <div class="padding"></div>
-
- <div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/Ruling_ignored_our_objections_to_the_seizure_of_popcorn_time_no___domstolkontroll_.html">Ruling ignored our objections to the seizure of popcorn-time.no (#domstolkontroll)</a></div>
- <div class="date">13th February 2017</div>
- <div class="body"><p>A few days ago, we received the ruling from
-<a href="http://people.skolelinux.org/pere/blog/A_day_in_court_challenging_seizure_of_popcorn_time_no_for__domstolkontroll.html">my
-day in court</a>. The case in question is a challenge of the seizure
-of the DNS domain popcorn-time.no. The ruling simply did not mention
-most of our arguments, and seemed to take everything ØKOKRIM said at
-face value, ignoring our demonstration and explanations. But it is
-hard to tell for sure, as we still have not seen most of the documents
-in the case and thus were unprepared and unable to contradict several
-of the claims made in court by the opposition. We are considering an
-appeal, but it is partly a question of funding, as it is costing us
-quite a bit to pay for our lawyer. If you want to help, please
-<a href="http://www.nuug.no/dns-beslag-donasjon.shtml">donate to the
-NUUG defense fund</a>.</p>
-
-<p>The details of the case, as far as we know it, is available in
-Norwegian from
-<a href="https://www.nuug.no/news/tags/dns-domenebeslag/">the NUUG
-blog</a>. This also include
-<a href="https://www.nuug.no/news/Avslag_etter_rettslig_h_ring_om_DNS_beslaget___vurderer_veien_videre.shtml">the
-ruling itself</a>.</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/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn</a>, <a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett</a>.
-
-
- </div>
- </div>
- <div class="padding"></div>
-
- <div class="entry">
- <div class="title"><a href="http://people.skolelinux.org/pere/blog/A_day_in_court_challenging_seizure_of_popcorn_time_no_for__domstolkontroll.html">A day in court challenging seizure of popcorn-time.no for #domstolkontroll</a></div>
- <div class="date"> 3rd February 2017</div>
- <div class="body"><p align="center"><img width="70%" src="http://people.skolelinux.org/pere/blog/images/2017-02-01-popcorn-time-in-court.jpeg"></p>
-
-<p>On Wednesday, I spent the entire day in court in Follo Tingrett
-representing <a href="https://www.nuug.no/">the member association
-NUUG</a>, alongside <a href="https://www.efn.no/">the member
-association EFN</a> and <a href="http://www.imc.no">the DNS registrar
-IMC</a>, challenging the seizure of the DNS name popcorn-time.no. It
-was interesting to sit in a court of law for the first time in my
-life. Our team can be seen in the picture above: attorney Ola
-Tellesbø, EFN board member Tom Fredrik Blenning, IMC CEO Morten Emil
-Eriksen and NUUG board member Petter Reinholdtsen.</p>
-
-<p><a href="http://www.domstol.no/no/Enkelt-domstol/follo-tingrett/Nar-gar-rettssaken/Beramming/?cid=AAAA1701301512081262234UJFBVEZZZZZEJBAvtale">The
-case at hand</a> is that the Norwegian National Authority for
-Investigation and Prosecution of Economic and Environmental Crime (aka
-Økokrim) decided on their own, to seize a DNS domain early last
-year, without following
-<a href="https://www.norid.no/no/regelverk/navnepolitikk/#link12">the
-official policy of the Norwegian DNS authority</a> which require a
-court decision. The web site in question was a site covering Popcorn
-Time. And Popcorn Time is the name of a technology with both legal
-and illegal applications. Popcorn Time is a client combining
-searching a Bittorrent directory available on the Internet with
-downloading/distribute content via Bittorrent and playing the
-downloaded content on screen. It can be used illegally if it is used
-to distribute content against the will of the right holder, but it can
-also be used legally to play a lot of content, for example the
-millions of movies
-<a href="https://archive.org/details/movies">available from the
-Internet Archive</a> or the collection
-<a href="http://vodo.net/films/">available from Vodo</a>. We created
-<a href="magnet:?xt=urn:btih:86c1802af5a667ca56d3918aecb7d3c0f7173084&dn=PresentasjonFolloTingrett.mov&tr=udp%3A%2F%2Fpublic.popcorn-tracker.org%3A6969%2Fannounce">a
-video demonstrating legally use of Popcorn Time</a> and played it in
-Court. It can of course be downloaded using Bittorrent.</p>
-
-<p>I did not quite know what to expect from a day in court. The
-government held on to their version of the story and we held on to
-ours, and I hope the judge is able to make sense of it all. We will
-know in two weeks time. Unfortunately I do not have high hopes, as
-the Government have the upper hand here with more knowledge about the
-case, better training in handling criminal law and in general higher
-standing in the courts than fairly unknown DNS registrar and member
-associations. It is expensive to be right also in Norway. So far the
-case have cost more than NOK 70 000,-. To help fund the case, NUUG
-and EFN have asked for donations, and managed to collect around NOK 25
-000,- so far. Given the presentation from the Government, I expect
-the government to appeal if the case go our way. And if the case do
-not go our way, I hope we have enough funding to appeal.</p>
-
-<p>From the other side came two people from Økokrim. On the benches,
-appearing to be part of the group from the government were two people
-from the Simonsen Vogt Wiik lawyer office, and three others I am not
-quite sure who was. Økokrim had proposed to present two witnesses
-from The Motion Picture Association, but this was rejected because
-they did not speak Norwegian and it was a bit late to bring in a
-translator, but perhaps the two from MPA were present anyway. All
-seven appeared to know each other. Good to see the case is take
-seriously.</p>
-
-<p>If you, like me, believe the courts should be involved before a DNS
-domain is hijacked by the government, or you believe the Popcorn Time
-technology have a lot of useful and legal applications, I suggest you
-too <a href="http://www.nuug.no/dns-beslag-donasjon.shtml">donate to
-the NUUG defense fund</a>. Both Bitcoin and bank transfer are
-available. If NUUG get more than we need for the legal action (very
-unlikely), the rest will be spend promoting free software, open
-standards and unix-like operating systems in Norway, so no matter what
-happens the money will be put to good use.</p>
-
-<p>If you want to lean more about the case, I recommend you check out
-<a href="https://www.nuug.no/news/tags/dns-domenebeslag/">the blog
-posts from NUUG covering the case</a>. They cover the legal arguments
-on both sides.</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/nuug">nuug</a>, <a href="http://people.skolelinux.org/pere/blog/tags/offentlig innsyn">offentlig innsyn</a>, <a href="http://people.skolelinux.org/pere/blog/tags/opphavsrett">opphavsrett</a>.
-
-
- </div>
- </div>
- <div class="padding"></div>
-
projects / homepage.git / blobdiff