Category Archives: Linux

I’ve been really annoyed at Skype for this weird behavior: When I was on a call, the audio worked fine. But when someone was calling me, I only got the small notification window but no ringing sound. I couldn’t figure this out for a long time, but now I found a solution: Open the system-wide […]

Your SSD needs some maintenance from time to time to perform well on the long run. After some use, it gets slower and slower if it isn’t told which parts of it are still in use and which hold only garbage. This is due to the internal workings of the disk that I won’t go […]

I use a Sansa Fuze music player that I’m quite happy with. It supports the USB Mass Storage protocol and thus can be used (and filled with music) just as any other USB flash drive. This means it is fully supported by all operating systems since it doesn’t need proprietary software running on a PC. […]

Unix timestamps (sometimes also called epoch) encode date and time in a single number, counting the seconds since January 1, 1970, 00:00 (UTC). The format is used througout a lot of software, but how can it be decoded to our common format? Naturally, there are web services like Epoch Converter, but how to decode it […]

Recently, I needed to recover a DSL password that only persisted in an old router (Draytek Vigor 2500/We). Since the web interface only shows the username, I tried the backup feature that dumps the entire configuration to a file that you can download. Unfortunately, this data comes in an encrypted form… which makes an excellent exercise […]

Ubuntu 10.04 (Lucid Lynx) features new panel applets called “indicator applets”. If you want to get rid of some of them, they can be removed by removing the corresponding package(s) using your favourite tool (Synaptic, aptitude, apt-get, …): indicator-me provides the menu with your avatar and your availability status indicator-messages provides the menu for email/Evolution, […]

What to do if you want to use mysqldump in a shared hosting environment without being able to access the shell (SSH…)? Use a Perl CGI script: #!/usr/bin/perl -w use strict; use CGI::Carp qw(fatalsToBrowser); print “Content-type: text/plain\nContent-disposition: attachment; filename=\”db_backup.sql\”\n\n”; print qx(mysqldump -uUSERNAME -pPASSWORD DATABASE 2>&1); Replace USERNAME, PASSWORD and DATABASE with the configuration data for […]

Linux is quite good at scheduling the CPU time of running programs: Even when a process is running which constantly uses up all processor power, it is still possible to use another (interactive) program nearly as fast as on an idle system. But if a process is doing heavy I/O operations (i.e. backup software), the […]

If you need to configure a backup of a MySQL database server, you shouldn’t simply copy it’s database files from /var/lib/mysql since they might be inconsistent (due to simultaneous changes). mysqldump is a safe choice for this task. I wrote a simple script for Debian that uses the pre-configured “debian-sys-maint” account and compresses the output: […]

This blog runs on a virtual server offered by Strato. They use Virtuozzo for virtualization which has a drawback: If you use top, free or other tools to show the current memory usage, not only your “slice” of the machine but more (all?) of the memory is measured. This doesn’t help much if you try […]