Yenya's World

Google Authenticator

Fri, 18 Nov 2011 14:30:00 +0100

For some time, I have been considering adding two-factor authentication to my systems in order to prevent break-ins in case somebody's workstation is compromised (which is a common attack vector these days). One of the systems for one-time passwords is Google Authenticator.

[... read more ...]

Dear Customer,

Mon, 03 Oct 2011 09:20:00 +0100

[...] we would also like to inform you about the following change in your network: a new address has been assigned to you: 2001:4cc8:...::/64.

[... read more ...]

High-Performance HTTP Servers

Wed, 15 Jun 2011 08:34:00 +0100

Yesterday I have read about Apache Traffic Server. My dear lazyweb, do you use something like that (or Nginx)? What is your main reason for using it? I wonder why use user-space solution, when IPVS works pretty well for load balancing.

Mysterious Source Code

Tue, 24 May 2011 14:15:00 +0100

About a month ago, I have spotted a two-page listing of source code in our printer room/kitchenette. I have glanced over it briefly, and during subsequent visits to the room, I became more and more fascinated by it. Finally, about a week ago, I have grabbed it for myself, because nobody seemed to care about it anymore. So here it is, in all its glory:

[... read more ...]

Lost GUI features

Mon, 23 May 2011 14:30:00 +0100

Contemporary GUI applications have several problems which, if I remember correctly, previous systems did not have. I wonder whether somebody else also considers it being a problem:

[... read more ...]

GNOME 3

Fri, 20 May 2011 19:45:00 +0100

After installing Fedora 15 in a virtual machine, I have decided to give GNOME 3 a try. Firstly, it is really slow over VNC. While GNOME 2 has been pretty usable for testing various new applications in a virtual machine, under GNOME 3 it is almost impossible. Here is a screenshot on which I will demonstrate my problems with GNOME 3:

[... read more ...]

Rethinking Cron

Tue, 03 May 2011 14:41:00 +0100

cron(8) is one of the oldest tools in UNIX. Despite of that, I think cron is not something to be proud of. In my opinion, it falls to the unfixable designs category. The recent attempts to fix it (factoring out atd(8), a dirty hack that is anacron(8), etc.) show some of the problems of cron. My recent experience confirms it:

[... read more ...]

git-diff(1) Dark Color Scheme

Fri, 01 Apr 2011 13:27:00 +0100

The default colored output of git-diff(1) and other commands is a bit ugly in my terminal with dark (green-on-black) color scheme. Here is how to fix it:

[... read more ...]

man(1) Surprise

Fri, 25 Mar 2011 09:46:00 +0100

Hello, this is your editor speaking, welcome to the "lesser known Linux feature of the day" series. Today we will cover an interesting feature of man(1) that your editor has just ran into. Try running the following command:

[... read more ...]

XFCE

Wed, 23 Mar 2011 18:09:00 +0100

The first alternative to GNOME I have decided to try is XFCE. In the LWN discussion, Jon Masters presented it as a viable replacement to GNOME. Also, it uses GTK+ like GNOME, so many applications can be the same (including, I have hoped, my window manager of choice, Sawfish. XFCE is definitely usable and configurable for power-user. Most (but not all) properties can also be set using their Settings manager, and thus XFCE should also be mostly usable for ordinary users. So far the problems include:

[... read more ...]

GNOME in the Shell

Tue, 22 Mar 2011 23:50:00 +0100

Yesterday, after reading The Grumpy Editor's GNOME 3 experience article at LWN, I have decided it is time to at least make an attempt to move away from GNOME, which (much like KDE 4) decided to use revolutionary instead of evolutionary development, and apparently continues in their feature removal crusade in the name of so called usability. Also, this might be a good chance to move away from Galeon after so many years.

[... read more ...]

New Odysseus

Wed, 09 Mar 2011 10:45:00 +0100

We have got a new hardware for our FTP server to replace our seven years old server. It is amazing how the old hardware is still in many aspects on par with state-of-the-art "average workstations". The old system had 12 GB of RAM, 8 TB of disks, and dual GbE. It was one of the first 64-bit x86 systems here at Faculty of Informatics. So, which principal improvements in server hardware the last seven years brought (apart from speed, of course)?

[... read more ...]

HW RAID versus SW RAID

Sat, 18 Dec 2010 11:45:00 +0100

As some of you know, I am not a huge fan of hardware RAID. In my opinion, software RAID can be faster in most cases. This is mainly because the operating system these days has several orders of magnitude larger buffer cache. This means more space for sorting, reordering, and prioritizing requests, fine tailored to the individual disks. Moreover, filesystems like XFS can be teached about the RAID structure of the underlying block device, and can optimize requests based on this knowledge.

[... read more ...]

DNSSEC Problems

Mon, 15 Nov 2010 17:50:00 +0100

In July, I have written about DNSSEC tools. Our zone is still not signed yet, but I have at least enabled DNSSEC valiadtion on our recursive servers at that time, asked the maintainer of the muni.cz domain about the DNSSEC enrollment process, and suggested we should discuss it further.

[... read more ...]

C++ Frequently Questioned Answers

Fri, 05 Nov 2010 11:28:00 +0100

As many of you probably know, I am not very fond of C++. Recently I've came across an excellent set of texts, which explicitly name many faults of this language.

[... read more ...]