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.
- --
-
-
- USENIX :login; Redundancy -Does Not Imply Fault Tolerance. Analysis of Distributed Storage -Reactions to Single Errors and Corruptions by Aishwarya Ganesan, -Ramnatthan Alagappan, Andrea C. Arpaci-Dusseau, and Remzi -H. Arpaci-Dusseau - -
- ZDNet -Why -RAID 5 stops working in 2009 by Robin Harris - -
- ZDNet -Why -RAID 6 stops working in 2019 by Robin Harris - -
- USENIX FAST'07 -Failure -Trends in a Large Disk Drive Population by Eduardo Pinheiro, -Wolf-Dietrich Weber and Luiz AndreÌ Barroso - -
- USENIX ;login: Data -Integrity. Finding Truth in a World of Guesses and Lies by Doug -Hughes - -
- USENIX FAST'08 -An -cAnalysis of Data Corruption in the Storage Stack - -L. N. Bairavasundaram, G. R. Goodson, B. Schroeder, A. C. -Arpaci-Dusseau, and R. H. Arpaci-Dusseau - -
- USENIX FAST'07 Disk -failures in the real world: what does an MTTF of 1,000,000 hours mean -to you? by B. Schroeder and G. A. Gibson. - -
- USENIX ;login: Are -Disks the Dominant Contributor for Storage Failures? A Comprehensive -Study of Storage Subsystem Failure Characteristics by Weihang -Jiang, Chongfeng Hu, Yuanyuan Zhou, and Arkady Kanevsky - -
- SIGMETRICS 2007 -An -analysis of latent sector errors in disk drives - -L. N. Bairavasundaram, G. R. Goodson, S. Pasupathy, and J. Schindler - -
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.
- -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.
+ +The layered video playout server created by Sveriges Television, +CasparCG Server, entered Debian +today. This completes many months of work to get the source ready to +go into Debian. The first upload to the Debian NEW queue happened a +month ago, but the work upstream to prepare it for Debian started more +than two and a half month ago. So far +the +casparcg-server package is only available for amd64, but I hope +this can be improved. The package is in contrib because it depend on +the non-free fdk-aac +library. The Debian package lack support for streaming web pages +because Debian is missing CEF, Chromium Embedded Framework. CEF is +wanted by several packages in Debian. But because the Chromium source +is not available as a build +dependency, it is not yet possible to upload CEF to Debian. I +hope this will change in the future.
+ +The reason I got involved is that +the Norwegian open channel +Frikanalen is starting to use CasparCG for our HD playout, and I +would like to have all the free software tools we use to run the TV +channel available as packages from the Debian project. The last +remaining piece in the puzzle is Open Broadcast Encoder, but it depend +on quite a lot of patched libraries which would have to be included in +Debian first.
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.
- -There are two commercial services available, -ShareLaTeX and -Overleaf. 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 -ShareLaTeX is free -software, while the latter is not. According to a -announcement from Overleaf, they plan to keep the ShareLaTeX code -base maintained as free software.
- -But these two are not the only alternatives. -Fidus Writer is another free -software solution with the -source available on github. I have not used it myself. Several -others can be found on the nice -alterntiveTo -web service. - -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. :)
- + +A fun way to learn how to program +Python is to follow the +instructions in the book +"Learn to program +with Minecraft", which introduces programming in Python to people +who like to play with Minecraft. The book uses a Python library to +talk to a TCP/IP socket with an API accepting build instructions and +providing information about the current players in a Minecraft world. +The TCP/IP API was first created for the Minecraft implementation for +Raspberry Pi, and has since been ported to some server versions of +Minecraft. The book contain recipes for those using Windows, MacOSX +and Raspian. But a little known fact is that you can follow the same +recipes using the free software construction game +Minetest.
+ +There is a +Minetest module implementing the same API, making it possible to +use the Python programs coded to talk to Minecraft with Minetest too. +I +uploaded +this module to Debian two weeks ago, and as soon as it clears the +FTP masters NEW queue, learning to program Python with Minetest on +Debian will be a simple 'apt install' away. The Debian package is +maintained as part of the Debian Games team, and +the +packaging rules are currently located under 'unfinished' on +Salsa.
+ +You will most likely need to install several of the Minetest +modules in Debian for the examples included with the library to work +well, as there are several blocks used by the example scripts that are +provided via modules in Minetest. Without the required blocks, a +simple stone block is used instead. My initial testing with a analog +clock did not get gold arms as instructed in the python library, but +instead used stone arms.
+ +I tried to find a way to add the API to the desktop version of +Minecraft, but were unable to find any working recipes. The +recipes +I found are only +working with a standalone Minecraft server setup. Are there any +options to use with the normal desktop version?
+ +As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
Recently, I needed to automatically check the copyright status of a -set of The Internet Movie database -(IMDB) entries, to figure out which one of the movies they refer -to can be freely distributed on the Internet. This proved to be -harder than it sounds. IMDB for sure list movies without any -copyright protection, where the copyright protection has expired or -where the movie is lisenced using a permissive license like one from -Creative Commons. These are mixed with copyright protected movies, -and there seem to be no way to separate these classes of movies using -the information in IMDB.
- -First I tried to look up entries manually in IMDB, -Wikipedia and -The Internet Archive, to get a -feel how to do this. It is hard to know for sure using these sources, -but it should be possible to be reasonable confident a movie is "out -of copyright" with a few hours work per movie. As I needed to check -almost 20,000 entries, this approach was not sustainable. I simply -can not work around the clock for about 6 years to check this data -set.
- -I asked the people behind The Internet Archive if they could -introduce a new metadata field in their metadata XML for IMDB ID, but -was told that they leave it completely to the uploaders to update the -metadata. Some of the metadata entries had IMDB links in the -description, but I found no way to download all metadata files in bulk -to locate those ones and put that approach aside.
- -In the process I noticed several Wikipedia articles about movies -had links to both IMDB and The Internet Archive, and it occured to me -that I could use the Wikipedia RDF data set to locate entries with -both, to at least get a lower bound on the number of movies on The -Internet Archive with a IMDB ID. This is useful based on the -assumption that movies distributed by The Internet Archive can be -legally distributed on the Internet. With some help from the RDF -community (thank you DanC), I was able to come up with this query to -pass to the SPARQL interface on -Wikidata: +
+A few hours ago, a new and improved version (2.4) of +the VLC +bittorrent plugin was uploaded to Debian. This new version +include a complete rewrite of the bittorrent related code, which seem +to make the plugin non-blocking. This mean you can actually exit VLC +even when the plugin seem to be unable to get the bittorrent streaming +started. The new version also include support for filtering playlist +by file extension using command line options, if you want to avoid +processing audio, video or images. The package is currently in Debian +unstable, but should be available in Debian testing in two days. To +test it, simply install it like this:
-SELECT ?work ?imdb ?ia ?when ?label -WHERE -{ - ?work wdt:P31/wdt:P279* wd:Q11424. - ?work wdt:P345 ?imdb. - ?work wdt:P724 ?ia. - OPTIONAL { - ?work wdt:P577 ?when. - ?work rdfs:label ?label. - FILTER(LANG(?label) = "en"). - } -} +apt install vlc-plugin-bittorrent-
If I understand the query right, for every film entry anywhere in -Wikpedia, it will return the IMDB ID and The Internet Archive ID, and -when the movie was released and its English title, if either or both -of the latter two are available. At the moment the result set contain -2338 entries. Of course, it depend on volunteers including both -correct IMDB and The Internet Archive IDs in the wikipedia articles -for the movie. It should be noted that the result will include -duplicates if the movie have entries in several languages. There are -some bogus entries, either because The Internet Archive ID contain a -typo or because the movie is not available from The Internet Archive. -I did not verify the IMDB IDs, as I am unsure how to do that -automatically.
- -I wrote a small python script to extract the data set from Wikidata -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 70 "disappearing" -entries (ie 2338-2097-171) are duplicate entries.
- -This is not too bad, given that The Internet Archive report to -contain 5331 -feature films at the moment, but it also mean more than 3000 -movies are missing on Wikipedia or are missing the pair of references -on Wikipedia.
- -I was curious about the distribution by release year, and made a -little graph to show how the amount of free movies is spread over the -years:
- -
I expect the relative distribution of the remaining 3000 movies to -be similar.
- -If you want to help, and want to ensure Wikipedia can be used to -cross reference The Internet Archive and The Internet Movie Database, -please make sure entries like this are listed under the "External -links" heading on the Wikipedia article for the movie:
+After it is installed, you can try to use it to play a file +downloaded live via bittorrent like this:
-* {{Internet Archive film|id=FightingLady}} -* {{IMDb title|id=0036823|title=The Fighting Lady}} +vlc https://archive.org/download/Glass_201703/Glass_201703_archive.torrent-
Please verify the links on the final page, to make sure you did not -introduce a typo.
- -Here is the complete list, if you want to correct the 171 -identified Wikipedia entries with broken links to The Internet -Archive: Q1140317, -Q458656, -Q458656, -Q470560, -Q743340, -Q822580, -Q480696, -Q128761, -Q1307059, -Q1335091, -Q1537166, -Q1438334, -Q1479751, -Q1497200, -Q1498122, -Q865973, -Q834269, -Q841781, -Q841781, -Q1548193, -Q499031, -Q1564769, -Q1585239, -Q1585569, -Q1624236, -Q4796595, -Q4853469, -Q4873046, -Q915016, -Q4660396, -Q4677708, -Q4738449, -Q4756096, -Q4766785, -Q880357, -Q882066, -Q882066, -Q204191, -Q204191, -Q1194170, -Q940014, -Q946863, -Q172837, -Q573077, -Q1219005, -Q1219599, -Q1643798, -Q1656352, -Q1659549, -Q1660007, -Q1698154, -Q1737980, -Q1877284, -Q1199354, -Q1199354, -Q1199451, -Q1211871, -Q1212179, -Q1238382, -Q4906454, -Q320219, -Q1148649, -Q645094, -Q5050350, -Q5166548, -Q2677926, -Q2698139, -Q2707305, -Q2740725, -Q2024780, -Q2117418, -Q2138984, -Q1127992, -Q1058087, -Q1070484, -Q1080080, -Q1090813, -Q1251918, -Q1254110, -Q1257070, -Q1257079, -Q1197410, -Q1198423, -Q706951, -Q723239, -Q2079261, -Q1171364, -Q617858, -Q5166611, -Q5166611, -Q324513, -Q374172, -Q7533269, -Q970386, -Q976849, -Q7458614, -Q5347416, -Q5460005, -Q5463392, -Q3038555, -Q5288458, -Q2346516, -Q5183645, -Q5185497, -Q5216127, -Q5223127, -Q5261159, -Q1300759, -Q5521241, -Q7733434, -Q7736264, -Q7737032, -Q7882671, -Q7719427, -Q7719444, -Q7722575, -Q2629763, -Q2640346, -Q2649671, -Q7703851, -Q7747041, -Q6544949, -Q6672759, -Q2445896, -Q12124891, -Q3127044, -Q2511262, -Q2517672, -Q2543165, -Q426628, -Q426628, -Q12126890, -Q13359969, -Q13359969, -Q2294295, -Q2294295, -Q2559509, -Q2559912, -Q7760469, -Q6703974, -Q4744, -Q7766962, -Q7768516, -Q7769205, -Q7769988, -Q2946945, -Q3212086, -Q3212086, -Q18218448, -Q18218448, -Q18218448, -Q6909175, -Q7405709, -Q7416149, -Q7239952, -Q7317332, -Q7783674, -Q7783704, -Q7857590, -Q3372526, -Q3372642, -Q3372816, -Q3372909, -Q7959649, -Q7977485, -Q7992684, -Q3817966, -Q3821852, -Q3420907, -Q3429733, -Q774474
+As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
I find it fascinating how many of the people being locked inside -the proposed border wall between USA and Mexico support the idea. The -proposal to keep Mexicans out reminds me of -the -propaganda twist from the East Germany government calling the wall -the âAntifascist Bulwarkâ after erecting the Berlin Wall, claiming -that the wall was erected to keep enemies from creeping into East -Germany, while it was obvious to the people locked inside it that it -was erected to keep the people from escaping.
- -Do the people in USA supporting this wall really believe it is a -one way wall, only keeping people on the outside from getting in, -while not keeping people in the inside from getting out?
+ +FNs +menneskerettighetserklæring artikkel 13 første punkt lyder som +følger:
+ ++Enhver har rett til å bevege seg fritt og til fritt å velge +oppholdssted innenfor en stats grenser. ++ +
Det er altsÃ¥ en menneskerett Ã¥ kunne bevege seg fritt i landet. +For Ã¥ bevege seg fritt i landet, sÃ¥ mÃ¥ en kunne bevege seg uten Ã¥ bli +sporet. Det vil i dagens samfunn innebære Ã¥ bevege seg uten Ã¥ legge +igjen digitale spor og uten Ã¥ være radiomerket. Hvis en vet at ens +bevegelser, hvor en befinner seg nÃ¥r, og hvem som befinner seg i +nærheten, blir samlet inn og gjort tilgjengelig for fremmede, det være +seg myndighetene eller private organisasjoner, sÃ¥ kan en ikke lenger +bevege seg fritt. Dette gjør at det er en forutsetning for Ã¥ ha glede +av retten til Ã¥ bevege seg fritt i landet at en motstÃ¥r fristelsen til +Ã¥ legge igjen digitale spor nÃ¥r en betaler for seg. Rettigheter som +ikke blir brukt, blir fjernet. Den eneste mÃ¥ten i dag Ã¥ unngÃ¥ Ã¥ legge +igjen digitale spor nÃ¥r en betaler for seg, er Ã¥ betale med kontanter, +samt takke nei til Ã¥ legge igjen navn og adresse (slik f.eks. Elkjøp +ber om — jeg sier de kan legge inn «anonym anonym» nÃ¥r +datasystemet deres trenger et navn). Personlig anbefaler jeg Ã¥ +konsekvent bruke kontant betaling nÃ¥r man beveger seg rundt, for Ã¥ +bidra til forsvaret av menneskerettighetene i Norge. Kanskje noe ogsÃ¥ +for deg? Merk at det ikke er tilstrekkelig for Ã¥ unngÃ¥ sporing Ã¥ +betale med kontanter, men det er et lite steg i riktig retning.
+ +Det er flere andre argumenter i tillegg til +menneskerettighetsargumentet for å bruke kontanter. I går hadde +Dagbladet en utmerket kommentar av sin journalist John Olav Egeland om +hvilket +kontantløst +diktatur som venter oss hvis mange nok slutter å insistere på å +betale med kontanter. Jeg anbefaler deg å lese den.
+ +Som vanlig, hvis du bruker Bitcoin og ønsker å vise din støtte til +det jeg driver med, setter jeg pris på om du sender Bitcoin-donasjoner +til min adresse +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b. +Merk, betaling med bitcoin er ikke anonymt. :)
At my nearby maker space, -Sonen, I heard the story that it -was easier to generate gcode files for theyr 3D printers (Ultimake 2+) -on Windows and MacOS X than Linux, because the software involved had -to be manually compiled and set up on Linux while premade packages -worked out of the box on Windows and MacOS X. I found this annoying, -as the software involved, -Cura, is free software -and should be trivial to get up and running on Linux if someone took -the time to package it for the relevant distributions. I even found -a request for adding into -Debian from 2013, which had seem some activity over the years but -never resulted in the software showing up in Debian. So a few days -ago I offered my help to try to improve the situation.
- -Now I am very happy to see that all the packages required by a -working Cura in Debian are uploaded into Debian and waiting in the NEW -queue for the ftpmasters to have a look. You can track the progress -on -the -status page for the 3D printer team.
- -The uploaded packages are a bit behind upstream, and was uploaded -now to get slots in the NEW -queue while we work up updating the packages to the latest -upstream version.
- -On a related note, two competitors for Cura, which I found harder -to use and was unable to configure correctly for Ultimaker 2+ in the -short time I spent on it, are already in Debian. If you are looking -for 3D printer "slicers" and want something already available in -Debian, check out -slic3r and -slic3r-prusa. -The latter is a fork of the former.
+ +Yesterday, I had the pleasure of watching on Frikanalen the OWASP +talk by Scott Helme titled +"What Weâve Learned From +Billions of Security Reports". I had not heard of the +Content +Security Policy standard nor its ability to "call home" when a +browser detect a policy breach (I do not follow web page design +development much these days), and found the talk very illuminating.
+ +The mechanism allow a web site owner to use HTTP headers to tell +visitors web browser which sources (internal and external) are allowed to +be used on the web site. Thus it become possible to enforce a "only +local content" policy despite web designers urge to fetch programs +from random sites on the Internet, like the one +enabling +the attack reported by Scott Helme earlier this year.
+ +Using CSP seem like an obvious thing for a site admin to implement +to take some control over the information leak that occur when +external sources are used to render web pages, it is a mystery more +sites are not using CSP? It is being +standardized under W3C these +days, and is supposed by most web browsers
+ +I managed to find a +Django middleware for implementing CSP and was happy to discover +it was already in Debian. I plan to use it to add CSP support to the +Frikanalen web site soon.
+ +As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
If you read my blog regularly, you probably know I am involved in +running and developing the Norwegian +TV channel Frikanalen. It is an open channel, allowing everyone +in Norway to publish videos on a TV channel with national coverage. +You can think of it as Youtube for national television. +In addition to distribution on RiksTV and Uninett, Frikanalen is also +available as a Kodi addon. The last few days I have updated the code +to add more features. A +new +and improved version 0.0.3 Frikanalen addon was just made +available via the Kodi repositories. This new version include a +option to browse videos by category, as well as free text search +in the video archive. It will now also show the video duration in the +video lists, which were missing earlier. A new and experimental +link to the HD video stream currently being worked on is provided, for +those that want to see what the CasparCG +output look like. The alternative is the SD video stream, generated +using MLT. CasparCG is controlled by our +mltplayout +server which instead of talking to mlt is giving PLAY instructions +to the CasparCG server when it is time to start a new program.
+ +By now, you are probably wondering what kind of content is being +played on the channel. These days, it is filled with technical +presentations like those from NUUG, +Debconf, Makercon, and TED, +but there are also some periods with +EMPT TV and +P7. + +
As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
Every mobile phone announce its existence over radio to the nearby -mobile cell towers. And this radio chatter is available for anyone -with a radio receiver capable of receiving them. Details about the -mobile phones with very good accuracy is of course collected by the -phone companies, but this is not the topic of this blog post. The -mobile phone radio chatter make it possible to figure out when a cell -phone is nearby, as it include the SIM card ID (IMSI). By paying -attention over time, one can see when a phone arrive and when it leave -an area. I believe it would be nice to make this information more -available to the general public, to make more people aware of how -their phones are announcing their whereabouts to anyone that care to -listen.
- -I am very happy to report that we managed to get something -visualizing this information up and running for -Oslo Skaperfestival 2017 -(Oslo Makers Festival) taking place today and tomorrow at Deichmanske -library. The solution is based on the -simple -recipe for listening to GSM chatter I posted a few days ago, and -will show up at the stand of à pen -Sone from the Computer Science department of the University of -Oslo. The presentation will show the nearby mobile phones (aka -IMSIs) as dots in a web browser graph, with lines to the dot -representing mobile base station it is talking to. It was working in -the lab yesterday, and was moved into place this morning.
- -We set up a fairly powerful desktop machine using Debian -Buster/Testing with several (five, I believe) RTL2838 DVB-T receivers -connected and visualize the visible cell phone towers using an -English version of -Hopglass. A fairly powerfull machine is needed as the -grgsm_livemon_headless processes from -gr-gsm converting -the radio signal to data packages is quite CPU intensive.
- -The frequencies to listen to, are identified using a slightly -patched scan-and-livemon (to set the --args values for each receiver), -and the Hopglass data is generated using the -patches -in my meshviewer-output branch. For some reason we could not get -more than four SDRs working. There is also a geographical map trying -to show the location of the base stations, but I believe their -coordinates are hardcoded to some random location in Germany, I -believe. The code should be replaced with code to look up location in -a text file, a sqlite database or one of the online databases -mentioned in -the github -issue for the topic. - -
If this sound interesting, visit the stand at the festival!
+ +As part of my involvement in +the Nikita +archive API project, I've been importing a fairly large lump of +emails into a test instance of the archive to see how well this would +go. I picked a subset of my +notmuch email database, all public emails sent to me via +@lists.debian.org, giving me a set of around 216 000 emails to import. +In the process, I had a look at the various attachments included in +these emails, to figure out what to do with attachments, and noticed +that one of the most common attachment formats do not have +an +official MIME type registered with IANA/IETF. The output from +diff, ie the input for patch, is on the top 10 list of formats +included in these emails. At the moment people seem to use either +text/x-patch or text/x-diff, but neither is officially registered. It +would be better if one official MIME type were registered and used +everywhere.
+ +To try to get one official MIME type for these files, I've brought +up the topic on +the +media-types mailing list. If you are interested in discussion +which MIME type to use as the official for patch files, or involved in +making software using a MIME type for patches, perhaps you would like +to join the discussion?
+ +As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
A little more than a month ago I wrote -how -to observe the SIM card ID (aka IMSI number) of mobile phones talking -to nearby mobile phone base stations using Debian GNU/Linux and a -cheap USB software defined radio, and thus being able to pinpoint -the location of people and equipment (like cars and trains) with an -accuracy of a few kilometer. Since then we have worked to make the -procedure even simpler, and it is now possible to do this without any -manual frequency tuning and without building your own packages.
- -The gr-gsm -package is now included in Debian testing and unstable, and the -IMSI-catcher code no longer require root access to fetch and decode -the GSM data collected using gr-gsm.
- -Here is an updated recipe, using packages built by Debian and a git -clone of two python scripts:
- --
-
-
- Start with a Debian machine running the Buster version (aka - testing). - -
- Run 'apt install gr-gsm python-numpy python-scipy - python-scapy' as root to install required packages. - -
- Fetch the code decoding GSM packages using 'git clone - github.com/Oros42/IMSI-catcher.git'. - -
- Insert USB software defined radio supported by GNU Radio. - -
- Enter the IMSI-catcher directory and run 'python - scan-and-livemon' to locate the frequency of nearby base - stations and start listening for GSM packages on one of them. - -
- Enter the IMSI-catcher directory and run 'python - simple_IMSI-catcher.py' to display the collected information. - -
Note, due to a bug somewhere the scan-and-livemon program (actually -its underlying -program grgsm_scanner) do not work with the HackRF radio. It does -work with RTL 8232 and other similar USB radio receivers you can get -very cheaply -(for example -from ebay), so for now the solution is to scan using the RTL radio -and only use HackRF for fetching GSM data.
- -As far as I can tell, a cell phone only show up on one of the -frequencies at the time, so if you are going to track and count every -cell phone around you, you need to listen to all the frequencies used. -To listen to several frequencies, use the --numrecv argument to -scan-and-livemon to use several receivers. Further, I am not sure if -phones using 3G or 4G will show as talking GSM to base stations, so -this approach might not see all phones around you. I typically see -0-400 IMSI numbers an hour when looking around where I live.
- -I've tried to run the scanner on a -Raspberry Pi 2 and 3 -running Debian Buster, but the grgsm_livemon_headless process seem -to be too CPU intensive to keep up. When GNU Radio print 'O' to -stdout, I am told there it is caused by a buffer overflow between the -radio and GNU Radio, caused by the program being unable to read the -GSM data fast enough. If you see a stream of 'O's from the terminal -where you started scan-and-livemon, you need a give the process more -CPU power. Perhaps someone are able to optimize the code to a point -where it become possible to set up RPi3 based GSM sniffers? I tried -using Raspbian instead of Debian, but there seem to be something wrong -with GNU Radio on raspbian, causing glibc to abort().
+ +My current home stereo is a patchwork of various pieces I got on +flee markeds over the years. It is amazing what kind of equipment +show up there. I've been wondering for a while if it was possible to +measure how well this equipment is working together, and decided to +see how far I could get using free software. After trawling the web I +came across an article from DIY Audio and Video on +Speaker +Testing and Analysis describing how to test speakers, and it listing +several software options, among them +AUDio MEasurement +System (AUDMES). It is the only free software system I could find +focusing on measuring speakers and audio frequency response. In the +process I also found an interesting article from NOVO on +Understanding +Speaker Specifications and Frequency Response and an article from +ecoustics on +Understanding +Speaker Frequency Response, with a lot of information on what to +look for and how to interpret the graphs. Armed with this knowledge, +I set out to measure the state of my speakers.
+ +The first hurdle was that AUDMES hadn't seen a commit for 10 years +and did not build with current compilers and libraries. I got in +touch with its author, who no longer was spending time on the program +but gave me write access to the subversion repository on Sourceforge. +The end result is that now the code build on Linux and is capable of +saving and loading the collected frequency response data in CSV +format. The application is quite nice and flexible, and I was able to +select the input and output audio interfaces independently. This made +it possible to use a USB mixer as the input source, while sending +output via my laptop headphone connection. I lacked the hardware and +cabling to figure out a different way to get independent cabling to +speakers and microphone.
+ +Using this setup I could see how a large range of high frequencies +apparently were not making it out of my speakers. The picture show +the frequency response measurement of one of the speakers. Note the +frequency lines seem to be slightly misaligned, compared to the CSV +output from the program. I can not hear several of these are high +frequencies, according to measurement from +Free Hearing Test +Software, an freeware system to measure your hearing (still +looking for a free software alternative), so I do not know if they are +coming out out the speakers. I thus do not quite know how to figure +out if the missing frequencies is a problem with the microphone, the +amplifier or the speakers, but I managed to rule out the audio card in my +PC by measuring my Bose noise canceling headset using its own +microphone. This setup was able to see the high frequency tones, so +the problem with my stereo had to be in the amplifier or speakers.
+ +Anyway, to try to role out one factor I ended up picking up a new +set of speakers at a flee marked, and these work a lot better than the +old speakers, so I guess the microphone and amplifier is OK. If you +need to measure your own speakers, check out AUDMES. If more people +get involved, perhaps the project could become good enough to +include in Debian? And if +you know of some other free software to measure speakers and amplifier +performance, please let me know. I am aware of the freeware option +REW, but I want something +that can be developed also when the vendor looses interest.
+ +As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
For noen dager siden publiserte Jon Wessel-Aas en bloggpost om -«Konklusjonen om datalagring som -EU-kommisjonen ikke ville at vi skulle få se». Det er en -interessant gjennomgang av EU-domstolens syn på snurpenotovervåkning -av befolkningen, som er klar på at det er i strid med -EU-lovgivingen.
- -Valgkampen går for fullt i Norge, og om noen få dager er siste -frist for å avgi stemme. En ting er sikkert, Høyre og Arbeiderpartiet -får ikke min stemme -denne -gangen heller. Jeg har ikke glemt at de tvang igjennom loven som -skulle pålegge alle data- og teletjenesteleverandører å overvåke alle -sine kunder. En lov som er vedtatt, og aldri opphevet igjen.
- -Det er tydelig fra diskusjonen rundt grenseløs digital overvåkning -(eller "Digital Grenseforsvar" som det kalles i Orvellisk nytale) at -hverken Høyre og Arbeiderpartiet har noen prinsipielle sperrer mot å -overvåke hele befolkningen, og diskusjonen så langt tyder på at flere -av de andre partiene heller ikke har det. Mange av -de som stemte -for Datalagringsdirektivet i Stortinget (64 fra Arbeiderpartiet, -25 fra Høyre) er fortsatt aktive og argumenterer fortsatt for å radere -vekk mer av innbyggernes privatsfære.
- -Når myndighetene demonstrerer sin mistillit til folket, tror jeg -folket selv bør legge litt innsats i å verne sitt privatliv, ved å ta -i bruk ende-til-ende-kryptert kommunikasjon med sine kjente og kjære, -og begrense hvor mye privat informasjon som deles med uvedkommende. -Det er jo ingenting som tyder på at myndighetene kommer til å være vår -privatsfære. -Det -er mange muligheter. Selv har jeg litt sans for -Ring, som er basert på p2p-teknologi -uten sentral kontroll, er fri programvare, og støtter meldinger, tale -og video. Systemet er tilgjengelig ut av boksen fra -Debian og -Ubuntu, og det -finnes pakker for Android, MacOSX og Windows. Foreløpig er det få -brukere med Ring, slik at jeg også bruker -Signal som nettleserutvidelse.
+ +Bittorrent is as far as I know, currently the most efficient way to +distribute content on the Internet. It is used all by all sorts of +content providers, from national TV stations like +NRK, Linux distributors like +Debian and +Ubuntu, and of course the +Internet archive. + +
Almost a month ago +a new +package adding Bittorrent support to VLC became available in +Debian testing and unstable. To test it, simply install it like +this:
+ ++apt install vlc-plugin-bittorrent ++ +
Since the plugin was made available for the first time in Debian, +several improvements have been made to it. In version 2.2-4, now +available in both testing and unstable, a desktop file is provided to +teach browsers to start VLC when the user click on torrent files or +magnet links. The last part is thanks to me finally understanding +what the strange x-scheme-handler style MIME types in desktop files +are used for. By adding x-scheme-handler/magnet to the MimeType entry +in the desktop file, at least the browsers Firefox and Chromium will +suggest to start VLC when selecting a magnet URI on a web page. The +end result is that now, with the plugin installed in Buster and Sid, +one can visit any +Internet +Archive page with movies using a web browser and click on the +torrent link to start streaming the movie.
+ +Note, there is still some misfeatures in the plugin. One is the +fact that it will hang and +block VLC +from exiting until the torrent streaming starts. Another is the +fact that it +will pick +and play a random file in a multi file torrent. This is not +always the video file you want. Combined with the first it can be a +bit hard to get the video streaming going. But when it work, it seem +to do a good job.
+ +For the Debian packaging, I would love to find a good way to test +if the plugin work with VLC using autopkgtest. I tried, but do not +know enough of the inner workings of VLC to get it working. For now +the autopkgtest script is only checking if the .so file was +successfully loaded by VLC. If you have any suggestions, please +submit a patch to the Debian bug tracking system.
+ +As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
On friday, I came across an interesting article in the Norwegian -web based ICT news magazine digi.no on -how -to collect the IMSI numbers of nearby cell phones using the cheap -DVB-T software defined radios. The article refered to instructions -and a recipe by -Keld Norman on Youtube on how to make a simple $7 IMSI Catcher, and I decided to test them out.
- -The instructions said to use Ubuntu, install pip using apt (to -bypass apt), use pip to install pybombs (to bypass both apt and pip), -and the ask pybombs to fetch and build everything you need from -scratch. I wanted to see if I could do the same on the most recent -Debian packages, but this did not work because pybombs tried to build -stuff that no longer build with the most recent openssl library or -some other version skew problem. While trying to get this recipe -working, I learned that the apt->pip->pybombs route was a long detour, -and the only piece of software dependency missing in Debian was the -gr-gsm package. I also found out that the lead upstream developer of -gr-gsm (the name stand for GNU Radio GSM) project already had a set of -Debian packages provided in an Ubuntu PPA repository. All I needed to -do was to dget the Debian source package and built it.
- -The IMSI collector is a python script listening for packages on the -loopback network device and printing to the terminal some specific GSM -packages with IMSI numbers in them. The code is fairly short and easy -to understand. The reason this work is because gr-gsm include a tool -to read GSM data from a software defined radio like a DVB-T USB stick -and other software defined radios, decode them and inject them into a -network device on your Linux machine (using the loopback device by -default). This proved to work just fine, and I've been testing the -collector for a few days now.
- -The updated and simpler recipe is thus to
- --
-
-
- start with a Debian machine running Stretch or newer, - -
- build and install the gr-gsm package available from -http://ppa.launchpad.net/ptrkrysik/gr-gsm/ubuntu/pool/main/g/gr-gsm/, - -
- clone the git repostory from https://github.com/Oros42/IMSI-catcher, - -
- run grgsm_livemon and adjust the frequency until the terminal -where it was started is filled with a stream of text (meaning you -found a GSM station). - -
- go into the IMSI-catcher directory and run 'sudo python simple_IMSI-catcher.py' to extract the IMSI numbers. - -
To make it even easier in the future to get this sniffer up and -running, I decided to package -the gr-gsm project -for Debian (WNPP -#871055), and the package was uploaded into the NEW queue today. -Luckily the gnuradio maintainer has promised to help me, as I do not -know much about gnuradio stuff yet.
- -I doubt this "IMSI cacher" is anywhere near as powerfull as -commercial tools like -The -Spy Phone Portable IMSI / IMEI Catcher or the -Harris -Stingray, but I hope the existance of cheap alternatives can make -more people realise how their whereabouts when carrying a cell phone -is easily tracked. Seeing the data flow on the screen, realizing that -I live close to a police station and knowing that the police is also -wearing cell phones, I wonder how hard it would be for criminals to -track the position of the police officers to discover when there are -police near by, or for foreign military forces to track the location -of the Norwegian military forces, or for anyone to track the location -of government officials...
- -It is worth noting that the data reported by the IMSI-catcher -script mentioned above is only a fraction of the data broadcasted on -the GSM network. It will only collect one frequency at the time, -while a typical phone will be using several frequencies, and not all -phones will be using the frequencies tracked by the grgsm_livemod -program. Also, there is a lot of radio chatter being ignored by the -simple_IMSI-catcher script, which would be collected by extending the -parser code. I wonder if gr-gsm can be set up to listen to more than -one frequency?
+ +This morning, the new release of the +Nikita +Noark 5 core project was +announced +on the project mailing list. The free software solution is an +implementation of the Norwegian archive standard Noark 5 used by +government offices in Norway. These were the changes in version 0.2 +since version 0.1.1 (from NEWS.md): + +
-
+
- Fix typos in REL names +
- Tidy up error message reporting +
- Fix issue where we used Integer.valueOf(), not Integer.getInteger() +
- Change some String handling to StringBuffer +
- Fix error reporting +
- Code tidy-up +
- Fix issue using static non-synchronized SimpleDateFormat to avoid + race conditions +
- Fix problem where deserialisers were treating integers as strings +
- Update methods to make them null-safe +
- Fix many issues reported by coverity +
- Improve equals(), compareTo() and hash() in domain model +
- Improvements to the domain model for metadata classes +
- Fix CORS issues when downloading document +
- Implementation of case-handling with registryEntry and document upload +
- Better support in Javascript for OPTIONS +
- Adding concept description of mail integration +
- Improve setting of default values for GET on ny-journalpost +
- Better handling of required values during deserialisation +
- Changed tilknyttetDato (M620) from date to dateTime +
- Corrected some opprettetDato (M600) (de)serialisation errors. +
- Improve parse error reporting. +
- Started on OData search and filtering. +
- Added Contributor Covenant Code of Conduct to project. +
- Moved repository and project from Github to Gitlab. +
- Restructured repository, moved code into src/ and web/. +
- Updated code to use Spring Boot version 2. +
- Added support for OAuth2 authentication. +
- Fixed several bugs discovered by Coverity. +
- Corrected handling of date/datetime fields. +
- Improved error reporting when rejecting during deserializatoin. +
- Adjusted default values provided for ny-arkivdel, ny-mappe, + ny-saksmappe, ny-journalpost and ny-dokumentbeskrivelse. +
- Several fixes for korrespondansepart*. +
- Updated web GUI:
+
-
+
- Now handle both file upload and download. +
- Uses new OAuth2 authentication for login. +
- Forms now fetches default values from API using GET. +
- Added RFC 822 (email), TIFF and JPEG to list of possible file formats. +
+
The changes and improvements are extensive. Running diffstat on +the changes between git tab 0.1.1 and 0.2 show 1098 files changed, +108666 insertions(+), 54066 deletions(-).
+ +If free and open standardized archiving API sound interesting to +you, please contact us on IRC +(#nikita on +irc.freenode.net) or email +(nikita-noark +mailing list).
+ +As usual, if you use Bitcoin and want to show your support of my +activities, please send Bitcoin donations to my address +15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
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-
@@ -876,7 +642,9 @@ one frequency?
- October (5) -
- November (1) +
- November (3) + +
- December (4)
@@ -1128,7 +896,7 @@ one frequency?
- 3d-printer (14) +
- 3d-printer (16)
- amiga (1) @@ -1136,15 +904,15 @@ one frequency?
- bankid (4) -
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- bootsystem (16) +
- bootsystem (17)
- bsa (2)
- chrpath (2) -
- debian (154) +
- debian (165)
- debian edu (158) @@ -1154,32 +922,36 @@ one frequency?
- dld (17) -
- docbook (24) +
- docbook (25)
- drivstoffpriser (4) -
- english (358) +
- english (396)
- fiksgatami (23) -
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- freeculture (30) +
- freeculture (32)
- freedombox (9) -
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- frikanalen (20)
- h264 (20)
- intervju (42) -
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- kart (20) +
- kodi (4) +
- ldap (9) +
- lego (4) +
- lenker (8)
- lsdvd (2) @@ -1188,21 +960,21 @@ one frequency?
- mesh network (8) -
- multimedia (39) +
- multimedia (42) -
- nice free software (9) +
- nice free software (11) -
- norsk (293) +
- norsk (300) -
- nuug (189) +
- nuug (191) -
- offentlig innsyn (33) +
- offentlig innsyn (34)
- open311 (2) -
- opphavsrett (65) +
- opphavsrett (72) -
- personvern (104) +
- personvern (108)
- raid (2) @@ -1216,23 +988,23 @@ one frequency?
- rss (1) -
- ruter (5) +
- ruter (6)
- scraperwiki (2) -
- sikkerhet (53) +
- sikkerhet (55)
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- standard (55) +
- standard (58)
- stavekontroll (6)
- stortinget (12) -
- surveillance (52) +
- surveillance (55)
- sysadmin (4) @@ -1240,11 +1012,13 @@ one frequency?
- valg (9) -
- video (59) +
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- video (72)
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