Creating A Local Yum Repository (CentOS) Sometimes it can be handy to set up your own repository to prevent from downloading the remote repository over and over again. This tutorial shows how to create a CentOS mirror for your local network. If you have to install multiple systems in your local network then all needed […]

What is DRBD? DRBD is an abbreviation of Distributed Replicated Block Device. DRBD is a block device which is designed to build high-availability clusters. This is done by mirroring a whole block device via (a dedicated) network. You could see it as a network RAID1. Pre-Configuration Requirements: I used two nodes with the following system […]

Configuring A High Availability Cluster (Heartbeat) On CentOS This guide shows how you can set up a two node, high-availability HTTP cluster with heartbeat on CentOS. Both nodes use the Apache web server to serve the same content. Pre-Configuration Requirements Assign hostname node01 to primary node with IP address 172.16.4.80 to eth0. Assign hostname node02 […]

Configure Postfix sample config Download Postfix config file [root@mail ~]#yum -y install postfix Loading “installonlyn” plugin Loading “fastestmirror” plugin Setting up Install Process Setting up repositories base 100% |=========================| 1.1 kB 00:00 updates 100% |=========================|951 B 00:00 addons 100% |=========================| 951 B 00:00 extras 100% |=========================| 1.1 kB 00:00 Loading mirror speeds from cached hostfile […]

Introduction You can monitor your system’s Web performance quite easily with graphical Linux tools. You’ll learn how to use several in this chapter, including MRTG, which is based on SNMP and monitors raw network traffic, and Webalizer, which tracks Web site hits. SNMP Most servers, routers and firewalls keep their operational statistics in object identifiers […]