Many years ago, when koffice was fresh and with few users, I -decided to test its presentation tool when making the slides for a -talk I was giving for NUUG on Japhar, a free Java virtual machine. I -wrote the first draft of the slides, saved the result and went to bed -the day before I would give the talk. The next day I took a plane to -the location where the meeting should take place, and on the plane I -started up koffice again to polish the talk a bit, only to discover -that kpresenter refused to load its own data file. I cursed a bit and -started making the slides again from memory, to have something to -present when I arrived. I tested that the saved files could be -loaded, and the day seemed to be rescued. I continued to polish the -slides until I suddenly discovered that the saved file could no longer -be loaded into kpresenter. In the end I had to rewrite the slides -three times, condensing the content until the talk became shorter and -shorter. After the talk I was able to pinpoint the problem – -kpresenter wrote inline images in a way itself could not understand. -Eventually that bug was fixed and kpresenter ended up being a great -program to make slides. The point I'm trying to make is that we -expect a program to be able to load its own data files, and it is -embarrassing to its developers if it can't.
- -Did you ever experience a program failing to load its own data -files from the desktop file browser? It is not a uncommon problem. A -while back I discovered that the screencast recorder -gtk-recordmydesktop would save an Ogg Theora video file the KDE file -browser would refuse to open. No video player claimed to understand -such file. I tracked down the cause being file --mime-type -returning the application/ogg MIME type, which no video player I had -installed listed as a MIME type they would understand. I asked for -file to change its -behavour and use the MIME type video/ogg instead. I also asked -several video players to add video/ogg to their desktop files, to give -the file browser an idea what to do about Ogg Theora files. After a -while, the desktop file browsers in Debian started to handle the -output from gtk-recordmydesktop properly.
- -But history repeats itself. A few days ago I tested the music -system Rosegarden again, and I discovered that the KDE and xfce file -browsers did not know what to do with the Rosegarden project files -(*.rg). I've reported the -rosegarden problem to BTS and a fix is commited to git and will be -included in the next upload. To increase the chance of me remembering -how to fix the problem next time some program fail to load its files -from the file browser, here are some notes on how to fix it.
- -The file browsers in Debian in general operates on MIME types. -There are two sources for the MIME type of a given file. The output from -file --mime-type mentioned above, and the content of the -shared MIME type registry (under /usr/share/mime/). The file MIME -type is mapped to programs supporting the MIME type, and this -information is collected from -the -desktop files available in /usr/share/applications/. If there is -one desktop file claiming support for the MIME type of the file, it is -activated when asking to open a given file. If there are more, one -can normally select which one to use by right-clicking on the file and -selecting the wanted one using 'Open with' or similar. In general -this work well. But it depend on each program picking a good MIME -type (preferably -a -MIME type registered with IANA), file and/or the shared MIME -registry recognizing the file and the desktop file to list the MIME -type in its list of supported MIME types.
- -The /usr/share/mime/packages/rosegarden.xml entry for -the -Shared MIME database look like this:
+ +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 df 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:
+ ++nfs: server nfsserver not responding, still trying ++ +
nfs: server nfsserver OK +
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.
+ +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.
+ +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.
+ +The content for a NFS mount point look similar to this:
--<?xml version="1.0" encoding="UTF-8"?> -<mime-info xmlns="http://www.freedesktop.org/standards/shared-mime-info"> - <mime-type type="audio/x-rosegarden"> - <sub-class-of type="application/x-gzip"/> - <comment>Rosegarden project file</comment> - <glob pattern="*.rg"/> - </mime-type> -</mime-info> +[...] +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 +[...]
This states that audio/x-rosegarden is a kind of application/x-gzip -(it is a gzipped XML file). Note, it is much better to use an -official MIME type registered with IANA than it is to make up ones own -unofficial ones like the x-rosegarden type used by rosegarden.
- -The desktop file of the rosegarden program failed to list -audio/x-rosegarden in its list of supported MIME types, causing the -file browsers to have no idea what to do with *.rg files:
- -- --% grep Mime /usr/share/applications/rosegarden.desktop -MimeType=audio/x-rosegarden-composition;audio/x-rosegarden-device;audio/x-rosegarden-project;audio/x-rosegarden-template;audio/midi; -X-KDE-NativeMimeType=audio/x-rosegarden-composition -% -
The fix was to add "audio/x-rosegarden;" at the end of the -MimeType= line.
- -If you run into a file which fail to open the correct program when -selected from the file browser, please check out the output from -file --mime-type for the file, ensure the file ending and -MIME type is registered somewhere under /usr/share/mime/ and check -that some desktop file under /usr/share/applications/ is claiming -support for this MIME type. If not, please report a bug to have it -fixed. :)
+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.
+ +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
+
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.
A little more than 11 years ago, one of the creators of Tor, and -the current President of the Tor -project, Roger Dingledine, gave a talk for the members of the -Norwegian Unix User group (NUUG). A -video of the talk was recorded, and today, thanks to the great help -from David Noble, I finally was able to publish the video of the talk -on Frikanalen, the Norwegian open channel TV station where NUUG -currently publishes its talks. You can -watch the live stream using a web -browser with WebM support, or check out the recording on the video -on demand page for the talk -"Tor: Anonymous -communication for the US Department of Defence...and you.".
- -Here is the video included for those of you using browsers with -HTML video and Ogg Theora support:
- - - -I guess the gist of the talk can be summarised quite simply: If you -want to help the military in USA (and everyone else), use Tor. :)
+ +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.
+ +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.
+ +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?
+ +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.
+ +Update 2017-03-13: Look like +The +Intercept report that US Senator Rand Paul confirm what I state above.
The isenkram -system is a user-focused solution in Debian for handling hardware -related packages. The idea is to have a database of mappings between -hardware and packages, and pop up a dialog suggesting for the user to -install the packages to use a given hardware dongle. Some use cases -are when you insert a Yubikey, it proposes to install the software -needed to control it; when you insert a braille reader list it -proposes to install the packages needed to send text to the reader; -and when you insert a ColorHug screen calibrator it suggests to -install the driver for it. The system work well, and even have a few -command line tools to install firmware packages and packages for the -hardware already in the machine (as opposed to hotpluggable hardware).
- -The system was initially written using aptdaemon, because I found -good documentation and example code on how to use it. But aptdaemon -is going away and is generally being replaced by -PackageKit, -so Isenkram needed a rewrite. And today, thanks to the great patch -from my college Sunil Mohan Adapa in the FreedomBox project, the -rewrite finally took place. I've just uploaded a new version of -Isenkram into Debian Unstable with the patch included, and the default -for the background daemon is now to use PackageKit. To check it out, -install the isenkram package and insert some hardware dongle -and see if it is recognised.
- -If you want to know what kind of packages isenkram would propose for -the machine it is running on, you can check out the isenkram-lookup -program. This is what it look like on a Thinkpad X230:
- -- --% isenkram-lookup -bluez -cheese -fprintd -fprintd-demo -gkrellm-thinkbat -hdapsd -libpam-fprintd -pidgin-blinklight -thinkfan -tleds -tp-smapi-dkms -tp-smapi-source -tpb -%p -
The hardware mappings come from several places. The preferred way -is for packages to announce their hardware support using -the -cross distribution appstream system. -See -previous -blog posts about isenkram to learn how to do that.
+ +For almost a year now, we have been working on making a Norwegian +Bokmål edition of The Debian +Administrator's Handbook. 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.
+ +A + +fresh PDF edition 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 +visit +Weblate and correct the error. The +state +of the translation including figures is a useful source for those +provide Norwegian bokmål screen shots and figures.
Yesterday I updated the -battery-stats -package in Debian with a few patches sent to me by skilled and -enterprising users. There were some nice user and visible changes. -First of all, both desktop menu entries now work. A design flaw in -one of the script made the history graph fail to show up (its PNG was -dumped in ~/.xsession-errors) if no controlling TTY was available. -The script worked when called from the command line, but not when -called from the desktop menu. I changed this to look for a DISPLAY -variable or a TTY before deciding where to draw the graph, and now the -graph window pop up as expected.
- -The next new feature is a discharge rate estimator in one of the -graphs (the one showing the last few hours). New is also the user of -colours showing charging in blue and discharge in red. The percentages -of this graph is relative to last full charge, not battery design -capacity.
- -The other graph show the entire history of the collected battery -statistics, comparing it to the design capacity of the battery to -visualise how the battery life time get shorter over time. The red -line in this graph is what the previous graph considers 100 percent: - -
In this graph you can see that I only charge the battery to 80 -percent of last full capacity, and how the capacity of the battery is -shrinking. :(
- -The last new feature is in the collector, which now will handle -more hardware models. On some hardware, Linux power supply -information is stored in /sys/class/power_supply/ACAD/, while the -collector previously only looked in /sys/class/power_supply/AC/. Now -both are checked to figure if there is power connected to the -machine.
- -If you are interested in how your laptop battery is doing, please -check out the -battery-stats -in Debian unstable, or rebuild it on Jessie to get it working on -Debian stable. :) The upstream source is available from github. -Patches are very welcome.
+ +A few days ago I ordered a small batch of +the ChaosKey, 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:
+ ++ ++% 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 +% +
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:
+ +-+% 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 +% +
As usual, if you use Bitcoin and want to show your support of my -activities, please send Bitcoin donations to my address -15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.
+Quite the difference. :) I bought a few more than I need, in case +someone want to buy one here in Norway. :)
+ +Update: The dongle was presented at Debconf last year. You might +find the talk +recording illuminating. 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.