Partitioning RAID / LVM on RAID

RAID devices can be partitioned, like ordinary disks can. This can be a real benefit on systems where one wants to run, for example, two disks in a RAID-1, but divide the system onto multiple different filesystems:

Read more on linux-raid.osdl.org

Installing PowerDNS (With MySQL Backend) And Poweradmin On CentOS 5.2

Version 1.0
Author: Falko Timme <ft [at] falkotimme [dot] com>
Last edited 01/15/2009

This article shows how you can install the PowerDNS nameserver (with MySQL backend) and the Poweradmin control panel for PowerDNS on a CentOS 5.2 system. PowerDNS is a high-performance, authoritative-only nameserver – in the setup described here it will read the DNS records from a MySQL database (similar to MyDNS), although other backends such as PostgreSQL are supported as well. Poweradmin is a web-based control panel for PowerDNS.

I do not issue any guarantee that this will work for you!

Read more on Howtoforge.com

Set Up A Linux PlayStation 3 Media Server (CentOS 5.2)

Version 1.0
Author: Andrew Colin Kissa <andrew [at] topdog [dot] za [dot] net>
Last edited 25/01/2009

Introduction

The Sony PlayStation 3 is a DLNA compatible device, DLNA is a framework where home electronics can share digital media and content seamlessly. This tutorial is a followup to the previous howto on Ubuntu. Given that I like most others use CentOS as their server distribution of choice, I find it fitting to run my DLNA server on it as well. Although several other open source media servers exist, I chose to use Fuppes due to its ease of use as well as built in support for transcoding.

By following this howto you will be able to create a server that will allow you to play digital media stored on the server via a DLNA capable device such as the Sony PS3, Nokia N95, etc.

Read more on Howtoforge.com

Dangerous coding errors revealed

The US National Security Agency has helped put together a list of the world’s most dangerous coding mistakes.

The 25 entry list contains errors that can lead to security holes or vulnerable areas that can be targeted by cyber criminals.

Experts say many of these errors are not well understood by programmers.

According to the SANS Institute in Maryland, just two of the errors led to more than 1.5m web site security breaches during 2008.

Read more on news.bbc.co.uk

How To Configure Software RAID To Send An Email When Something’s Wrong With RAID

Version 1.0
Author: Falko Timme <ft [at] falkotimme [dot] com>
Last edited 12/12/2008

This short guide explains how you can configure software RAID to send you an email when something’s wrong with RAID, for example if a hard drive fails. I’ve tested this on Debian Etch, but it should apply to all other distributions with minor adjustments to paths, etc.

Read more on Howtoforge.com

Setting Up A High-Availability Load Balancer With HAProxy/Wackamole/Spread On Debian Etch

Version 1.0
Author: Falko Timme <ft [at] falkotimme [dot] com>
Last edited 12/22/2008

This article explains how to set up a two-node load balancer in an active/passive configuration with HAProxy, Wackamole, and Spread on Debian Etch. The load balancer sits between the user and two (or more) backend Apache web servers that hold the same content. Not only does the load balancer distribute the requests to the two backend Apache servers, it also checks the health of the backend servers. If one of them is down, all requests will automatically be redirected to the remaining backend server. In addition to that, the two load balancer nodes monitor each other using Wackamole and Spread, and if the master fails, the slave becomes the master, which means the users will not notice any disruption of the service. HAProxy is session-aware, which means you can use it with any web application that makes use of sessions (such as forums, shopping carts, etc.).

From the HAProxy web site: “HAProxy is a free, very fast and reliable solution offering high availability, load balancing, and proxying for TCP and HTTP-based applications. It is particularly suited for web sites crawling under very high loads while needing persistence or Layer7 processing. Supporting tens of thousands of connections is clearly realistic with todays hardware. Its mode of operation makes its integration into existing architectures very easy and riskless, while still offering the possibility not to expose fragile web servers to the Net.”
Read more on Howtoforge.com

Routing for multiple uplinks/providers

A common configuration is the following, in which there are two providers that connect a local network (or even a single machine) to the big Internet.

There are usually two questions given this setup.

Read more on lartc.org