Gentoo : Xorg X Server 3D hardware acceleration
You need to have read/write permissions to /dev/dri/cardX to benefit from 3D hardware acceleration in Xorg X Server. On a Gentoo linux machine, this file has the following permissions set by default :
ls -l /dev/dri/card0
crw-rw---- 1 root video 226, 0 2009-10-14 16:12 /dev/dri/card0
Gentoo : Running Cacti with LigHTTPD
If you use Gentoo and tried to install Cacti with Lighttpd instead of Apache, chances are that you ran into this error message :
/usr/lib/python2.6/site-packages/WebappConfig/content.py:27: DeprecationWarning: the md5 module is deprecated; use hashlib instead
import md5, re, os, os.path
* Fatal error: Your configuration file sets the server type "Apache"
* Fatal error: but the corresponding package does not seem to be installed!
* Fatal error: Please "emerge >=www-servers/apache-1.3" or correct your settings.
* Fatal error(s) - aborting
Xfce4 : Bug with key bindings
There is currently a little bug in Xfce4 which prevents you to bind the key combinations involving SPACE and ESCAPE. For example you can’t bind
HAL + Xorg X server : Using HAL to set hardware specific configurations for Xorg Xserver
The Xorg X Server can now rely on HAL to get information about the hardware the machine is running. This allows the X Server to auto-configure most of its components such as keyboard / mouse / screen / graphic adapter. But there is still room for tweaking it if needed.
This post explains how to configure extra properties for a keyboard at the HAL level, so that X Server will correctly auto-configure it for you.
conky : integrating rTorrent downloads monitoring
Conky is a lightweight system monitoring tool. It has many built-in probes (processor load, memory usage, temperature sensors, etc), but it is still pretty easy to extend it if you don’t find the feature you need.
In this post I’ll describe my Conky setup and explain how to extend it to monitor your rTorrent downloads.
rTorrent is a great BitTorrent client which offers an XML-RPC interface to its core functions, making it easy to get the downloads status through scripting. You can read more about that in this previous post.
rTorrent : Probing downloads status through XML-RPC
rTorrent is a very efficient BitTorrent client for linux. It has a very small memory footprint, a very customizable configuration file, and exposes it’s internals through XML-RPC. This is convenient to implement 3rd party GUI or web interfaces.
Let’s see how to setup and use XML-RPC to probe rTorrent downloads.
VIM: using the modeline for file based customized editing parameters
The “modeline” is a common way to set (or override) VIM settings on a file by file basis. Let’s see a few of the key concepts of the VIM modeline.
Linux : SATA hot plug / unplug
I have 3 hard disks in SATA-to-eSATA external enclosure which I occasionally need to plug to perform backups and to unplug when done. I found it annoying to have to restart the whole computer at every turn, especially when SATA is supposed to bring hotplug abilities. If you mainboard / SATA chipset and disks support hot plugging and unplugging, you can do this by following those instructions.
SSH : Multiplexing connections
There is a feature in OpenSSH since v3.9 which allows multiple SSH connections with the same caracteristics (host, port, remote login) to be made through a single TCP connection. This is useful because you’ll have to authenticate only once, and besides the new SSH connections will be much faster to establish.
Linux : Configuring a network bridge for your Virtual Machines
My new center of interest those days being virtualization, I tried quite a few software starting with Xen, then QEMU, then KVM, and finally VirtualBox. But as far as giving a network access to the VM is concerned, I’ve always sticked to a network bridge for the reason that this makes the VM appear on the network just like any other computer of your network.
This post provided a sample script to setup a bridge suitable to use with all of the named virtualization softwares.