HOWTO: force filesystem check on reboot in a Linux system

Usually, only a superficial file system check is performed automatically on boot up, and it's sufficient; but sometimes it could be handy to force a full file system check (i. e., to run the Linux fsck utility) to ensure the FS is really OK.

1. Classic init (SysVinit): just reboot the system with a special option:

   # shutdown -rF now

2. systemd init: much more interesting: at the boot time, you need to append a special kernel command line parameter (e. g., you can specify it at the GRUB command line):

   linux /boot/vmlinuz root=UUID=... ro fsck.mode=force

P. S. It should then check all the filesystems enabled for checking in /etc/fstab.

References:

1. man shutdown
2. man systemd-fsck
3. man fstab
4. man fsck

HOWTO: play MIDI files with VLC in Debian

It's very easy! And should also work for Ubuntu (and other Debian derivatives).

0. First of all, make sure you have already installed the VLC media player:

   # apt-get install vlc

1. Install the FluidSynth plugin:

   # apt-get install vlc-plugin-fluidsynth

2. Enjoy!
   You can open your file either with the VLC GUI, or from the CLI, e. g.:
   

   $ vlc ~/Music/MyFavoriteSong.midi

HOWTO: preventing aptitude from breaking the APT package setup

Initial conditions:

• usually, you use apt-get (from the apt package) for Debian package maintenance (installing, removing, upgrading etc.);
• sometimes you launch aptitude (aptitude package) to do some work;
• after doing some work with apt-get, you notice that aptitude hasn't caught up with the current package state (i. e., it wants to install / remove some package(s) just from the start).

Solution: hide (or delete) the outdated package states file from aptitude (note: it'll overwrite an old backup, "/var/lib/aptitude/pkgstates.old", if present):

$ cd /var/lib/aptitude
# mv pkgstates pkgstates.old

P. S. This should also work for Debian derivatives (e. g. Ubuntu).

Hardware accident: Chinese LED lantern turned into a firework

Device brand / model: Yajia YJ-6812
Description: a Chinese lantern with 32 LEDs (quite bright really; 2 levels of brightness); rechargeable (no information on battery currently); without any external power adapters (plugged directly into AC socket by a simple 2-wire cable). Bought on a local Ukrainian (Vinnytsia city) market. The design somewhat reminds of a kind of grater.

Software: MediaInfo

Currently, MediaInfo is probably the best free & open-source utility for extracting technical info (metadata) from multimedia files (most frequently, containers with audio and video streams).
It's quite portable (runs on various Linux distributions, MS Windows, Apple Mac OS X, FreeBSD etc.; released regularly in source and compiled binary forms) and comes with CLI and GUI interfaces.

External links:

• MediaInfo on MediaArea (official website)
• MediaInfo on SourceForge (project page)
  • (redirect to the official website)
• MediaInfo - Wikipedia