PUBLIC MARKS from camel with tag linux

If you have a server with more than 4GB RAM and want to install a 32bit Debian Etch on it (following this tutorial: Debian Etch And Xen From The Debian Repository), you'd expect the Xen-PAE kernel to see all your RAM because the Xen-PAE kernel supports up to 64GB RAM. In fact, it recognizes only about 3.3GB RAM due to a bug in the GRUB bootloader. This article explains how you can fix GRUB so that all your RAM gets recognized. I do not issue any guarantee that this will work for you!

fwknop stands for the "FireWall KNock OPerator", and implements an authorization scheme called Single Packet Authorization (SPA). This method of authorization is based around a default-drop packet filter (fwknop supports both iptables on Linux systems and ipfw on FreeBSD and Mac OS X systems) and libpcap.

Pound is a reverse-proxy load balancing server. It accepts requests from HTTP / HTTPS clients and distributes them to one or more Web servers. The HTTPS requests are decrypted and passed to the back-ends as plain HTTP. It will act as: a) Server load balancer b) Reverse proxy server c) Apache reverse proxy etc d) It can detects when a backend server fails or recovers, and bases its load balancing decisions on this information: if a backend server fails, it will not receive requests until it recovers e) It can decrypts https requests to http ones f) Rejects incorrect requests h) It can be used in a chroot environment (security feature)

mysqlreport is a Perl script that displays a well-formatted report of important MySQL status variables (taken from MySQL's SHOW STATUS; output) that can help you gain an understanding of what is happening under MySQL's hood. It can help diagnose problems.

Mac-On-Linux provides a virtual machine for running MacOS, MacOSX and Linux (in progress) on your PowerPC machine.

How do I format and connect to an iSCSI Volume under Debian / Ubuntu Linux?

Super Grub Disk se veut une petite boite à outils puissante permettant de démarrer sur son système d’exploitation préféré en cas de défaillance, retrouver la mire de windows après une installation d’une distribution linux ou restaurer GRUB en cas de perte.

Prism, anciennement appelé webrunner, est un petit navigateur mono-site dépourvu de toutes interfaces (pas de menus, pas de boutons, ...) le rendant ainsi ultra-rapide. Cet article explique comment l'installer et l'utiliser sur un système d'exploitation Linux. Le but principal de ce logiciel est donc de permettre à l'utilisateur d'accéder facilement et rapidement à des applications en ligne, qu'il consulte très régulièrement (webmail, lecteur de flux RSS ...). On se retrouve ainsi avec un programme qui réunit le meilleur des deux mondes : les applications desktop locales et les applications web en ligne.

La commande netstat, sous Linux, a des fonctionalités bien pratique. Elle peut par exemple, permettre de connaître le nombre exact de connexions sur un port donn

This article explains how to set up a two-node load balancer in an active/passive configuration with Pound and keepalived 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 keepalived, and if the master fails, the slave becomes the master, which means the users will not notice any disruption of the service. Pound is session-aware, which means you can use it with any web application that makes use of sessions (such as forums, shopping carts, etc.).

This guide describes how to set up a full email solution in Debian Linux (all code is from Debian Etch). I was asked to design a secure, scalable, portable solution for a small company. While the guide references many 'servers', the company only had 4 physical machines, Xen was used to virtualize the entire solution. That particular aspect of the system is not discussed in this guide, although I will try to get it into the next revision.

This article explains how to set up a two-node load balancer in an active/passive configuration with HAProxy and keepalived 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 keepalived, 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.).

Since version 5, MySQL comes with built-in support for master-master replication, solving the problem that can happen with self-generated keys. In former MySQL versions, the problem with master-master replication was that conflicts arose immediately if node A and node B both inserted an auto-incrementing key on the same table. The advantages of master-master replication over the traditional master-slave replication are that you don't have to modify your applications to make write accesses only to the master, and that it is easier to provide high-availability because if the master fails, you still have the other master.

Ce petit guide explique quelques combinaisons de touches à utiliser lorsqu'un système Linux est completement bloqué.

TCPdump est un outil en ligne de commande pour écouter ce qui se passe sur une interface réseau. Il est disponible sur la plupart des operating system (Linux, Mac, Wins…). Comme son nom ne l’indique pas il est capable de déchiffrer tout les paquets IP.

Iperf est un des outils indispensable pout tout administrateur réseau qui se respecte. En effet, ce logiciel de mesure de performance réseau, diponible sur de nombreuses plateformes (Linux, BSD, Mac, Windows…), se présente sous la forme d’une ligne de commande à executer sur deux machines disposées aux extrémités du réseau à tester.

This guide is about mod_macro, which makes the job of managing an Apache webserver much easier, or just for the home developer with several test pages or projects. I will explain how to get it running and give some examples of how I use the module, to help you get started with using it.

How do I add cron job under Linux or UNIX like operating system?

Rsyslog is an enhanced multi-threaded syslogd supporting, among others, MySQL, syslog/tcp, RFC 3195, permitted sender lists, filtering on any message part, and fine grain output format control. It is quite compatible to stock sysklogd and can be used as a drop-in replacement. Its advanced features make it suitable for enterprise-class, encryption protected syslog relay chains while at the same time being very easy to setup for the novice user. An optional web interface - phpLogCon - can be used to visualize all data online."

Cron Job Prevent the sending of errors and output To prevent the sending of errors and output, add any one of the following at the end of the line for each cron job to redirect output to /dev/null.