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Showing posts from 2016

debugging systemd service in Raspbian 8 through core dumps

Taking notes on what I did to enable core dumps from a service running under systemd. Not sure which of these were strictly necessary, though. Added to /etc/security/limits.conf * soft core unlimited * hard core unlimited Add ed to /etc/sysctl.d/core.conf kernel.core_pattern = core-%e-sig%s-user%u-group%g-pid%p-time%t kernel.core_uses_pid = 1 fs.suid_dumpable = 2 Add ed to  /lib/systemd/system/ my-service .ser vi ce [Service] -section LimitCORE=infinity created world-writable dump directory sudo mkdir -p /var/lib/coredumps sudo chown nobody:nogroup /var/lib/coredumps sudo chmod a+w /var/lib/coredumps/ Verified that limits are ok grep core /proc/$(pgrep damon-process-name-here )/limits Verified that core gets dumped sudo kill -SIGABRT  $(pgrep  damon-process-name-here ) gdb /bin/ my-daemon /var/lib/coredumps/core*

HP network printing in Ubuntu fails with m_Job initialization failed with error = 48

Note to self: next time my HP network printer fails to work properly in Linux, use hpsetup -i to install the printer. Don't rely on the easy looking graphical user interface to install the printer. D [06/Dec/2016:22:20:54 +0200] [Job 5] Processing page 1... D [06/Dec/2016:22:20:54 +0200] [Job 5] Set job-printer-state-message to "Processing page 1...", current level=INFO D [06/Dec/2016:22:20:54 +0200] [Job 5] prnt/hpcups/Hbpl1.cpp 52: Hbpl1 constructor : m_szLanguage = HBPL1STATE: +hplip.plugin-error D [06/Dec/2016:22:20:54 +0200] [Job 5] prnt/hpcups/HPCupsFilter.cpp 486: m_Job initialization failed with error = 48 D [06/Dec/2016:22:20:54 +0200] [Job 5] PID 3860 (/usr/lib/cups/filter/hpcups) stopped with status 1. D [06/Dec/2016:22:20:54 +0200] [Job 5] Hint: Try setting the LogLevel to "debug" to find out more. D [06/Dec/2016:22:20:54 +0200] [Job 5] prnt/backend/hp.c 919: ERROR: null print job total=0

Macports Octave build hangs on El Capitan

While trying to install Octave from Macports on El Capitan, the build hangs during atlas compilation. Existing bug reports  don't really provide a solution. Luckily, Octave wiki provides a solution in  4.3.1 Simple Installation Instructions   sudo port install atlas +gcc5   sudo port install arpack -acclerate +atlas   sudo port install octave

Personal streaming music server

Idea I would like to have a private Spotify / Google Music / Apple music like setup. For free. As I already have bought the music once in the past. Music files would be stored at home, but accessible anywhere. This way I could listen to all my favourite songs on the go. And do this with low end smartphones which have limited storage capacity but flat fee 3G/4G network access. Server Hardware Raspberry PI to start with. Software Tonido Both the server and the mobile application keep on crashing Depends on Tondo servers to be available. I can only hope their freemium business model is sustainable forever. Madsonic Implemented in Java Needs to be configured for low ram from defaults #MADSONIC_INIT_MEMORY=192 #MADSONIC_MAX_MEMORY=384 MADSONIC_INIT_MEMORY=32 MADSONIC_MAX_MEMORY=128 You need patience to start it up on a Raspi model B  Auto start for now /etc/rc.local: su -c /var/madsonic/standalone/madsonic.sh pi Mobile application TBD app