Exceeding 10.000 km with E-Bike

5th April 2017

As described in Commuting to Work with an E-Bike I drive to my work place using an e-bike. As I found out that using a bike is a viable alternative to public transport I bought a better e-bike after about a year. I bought my first e-bike in March 2015, my second in December 2015, and used it since…

Wiping Disks

20th March 2017

How fast can you wipe a complete disk? For this I dumped zeros to a MS Windows partition based on an SSD formatted with NTFS. [root@i7 ~]# time dd if=/dev/zero of=/dev/sda1 bs=1M dd: error writing '/dev/sda1': No space left on device 81920+0 records in 81919+0 records out 85898297344 bytes (86 GB,…

Make USB Stick Bootable

15th March 2017

In various forums one reads that one should use dd to copy a ISO image to an USB stick. Although this works, more often you do not want to use a ISO image but rather copy a Linux system at hand. First you mount the root filesystem of the new USB stick, then mount /boot within a chroot. Finally use…

Switching from ext4 to btrfs

13th February 2017

Hearing all these wonder stories about btrfs I decided to give btrfs a try. Additionally I encrypted my SSD using LUKS. The relevant entries in the Arch WIKI are: Setting up LUKS and btrfs. Here is the list of commands I used. 1. I saved my data from SSD using tar and saved tar-file on…

Downgrading PulseAudio with downgrade.sh

30th January 2017

Just upgraded PulseAudio from 9.0-1 => 10.0-2, which was no good, as I was left with no sound. The bash script downgrade.sh given in Github by Gordian Edenhofer saved the day. Sound is back. The script is for Arch Linux. Usage: downgrade.sh libpulse pulseaudio pulseaudio-bluetooth From now on I…

Victoria Kaspi Public Lecture: The Cosmic Gift of Neutron Stars

12th January 2017

A very fine introduction by Prof. Dr. Victoria Kaspi to neutron stars, pulsars, magnetars, binary pulsars. Explaining their use in test for general relativity, and detection of gravitational waves. She also mentions Einstein@Home. Homepage of Prof. Kaspi is here. A recent (6-Jan-2017) observation…

Arnold Heinrich Klausmeier

1st January 2017

On 16-Dec-2016 my father died after a long and suffering disease. Born on 28-Nov-1934, he witnessed World-War-II, 1939-1945, separation of Germany, Suez Crisis, 1956, Cuban Missile Crisis, 1962, Vietnam War, Chinese Cultural Revolution, 1966-1976, but also the German reunification, and the Euro. As…

Cablesurf Channel Statistics

31st December 2016

Cablesurf is a German internet-cable-provider. They deliver Technicolor modem and set-top boxes to the end customers. My cable modem model is: HW Revision 1.0 VENDOR Technicolor BOOT Revision 2.4.0 SW Revision STDD.01.05 MODEL TC7200.20 …

slurmd confused of pid-file

14th December 2016

I wrote on SLURM used on Ubuntu here. As I moved to Arch Linux I of course use the fine AUR package slurm-llnl maintained by Gordian Edenhofer. After upgrading to version 16.05.7-1 I noticed the following: If slurmd is started by systemd then the pid-file specified for systemd in…

Operation Costs Measured in CPU Clock Cycles

22nd November 2016

I have written on the merits of 64-bit vs 32-bit, or on the AMD Bulldozer CPU Architecture Overview. An article in ithare.com gave a very good overview about the relative performance of various CPU operations. Below is the graphic: The above image is from IT Hare on Soft.ware. Also see the often…

Statistics of this Blog: Crossed 40.000 Views

12th November 2016

This blog was viewed more than 40.000 times and had more than 30.000 visitors. As in this post, here are the numbers: All these increases by 10.000 views all come roughly every eight months, see 30.000 (Jan-2016), 20.000 (Apr-2015), 10.000 (Sep-2014). So I kind of have reached a steady-state. The…

Bluetooth Headphones in Arch Linux

26th October 2016

There is a big difference between noise-cancelling headphones, and classical headphones without noise-cancelling ability! Especially when you use them in a noisy environment, like a plane or a large office bureau. Inspired by a positive review of the Bose headphones by Marques Brownlee, I bought…

Running bacman in parallel

18th October 2016

The mailing list for pacman-dev contains an interesting thread when rebuilding packages from source, i.e., running bacman in parallel. Gordian Edenhofer ran some tests on performance when running one, two, three, up to six jobs in parallel. The results, below, clearly show that using all your cores…

Interior of Dell XPS-13 and Acer Aspire

11th October 2016

Here is a photo when the Dell XPS-13 is opened: And here is the Acer Aspire opened:

Why does deep and cheap learning work so well?

8th October 2016

Very interesting. -- -- -- Quote -- -- -- Why does deep and cheap learning work so well Lin & Tegmark 2016 Deep learning works remarkably well, and has helped dramatically improve the state-of-the-art in areas ranging from speech recognition, translation, and visual object recognition to…

Setting Keyboard-Language in IceWM

4th October 2016

If you start IceWM from GNOME, you can set your language settings in ~/.icewm/startup For example #!/bin/sh setxkbmap de Setting all available window-managers is done in /usr/share/xsessions Example: For starting icewm you can use the following configuration file…

LibreOffice Impress Becoming Very Slow After Copy/Paste

28th September 2016

LibreOffice Impress version 5.1 and 5.2 for Linux kernel 4.7 becomes extremely slow, if one copies some slides multiple times. This behaviour can be reproduced on laptops, machines with and without graphic card. For example, take a random presentation and copy one slide 20 times by pressing ctrl-v.…

SSD Speed on Dell XPS 13 9350

27th July 2016

In Hard-Disk and SSD Speed Comparisons I compared a Mushkin SSD with 60 GB against a ADATA with 128 GB against a Seagate 1 TB hard disk drive. The SSD's had roughly three times the speed of the hard disk drive. I.e., 380 MB/s vs. 134 MB/s for reading Mushkin vs. Seagate, and 297 MB/s vs. 131 MB/s…

Considerations when converting from WordPress.com to Hugo

13th June 2016

At times WordPress.com uses its user base to experiment with some half baked new features, see for example Classical editor in WordPress.com, or see this Hello Jekyll, bye Wordpress.com! These are the times when I consider migrating from WordPress.com to another blogging platform. Usually after…

Exporting Exchange/Outlook GAL to vCard

5th June 2016

This post is about the Microsoft Exchange GAL, i.e., the global address list. The task is to export the data in the GAL to vCard format. Microsoft Outlook stores local caches of the GAL in %userprofile%\Local Settings\Application Data\Microsoft\Outlook, see Administering the offline address book in…