Recently i was migrating an Apache HTTP Server (httpd) server from one linux machine to another. The problem was, that on the source linux machine Apache HTTP Server (httpd) was a custom compiled 2.4.4 and we were having constant problems when patching the linux machine (openssl libraries etc.). So we decided to replace the custom compiled Apache HTTP Server (httpd) with […]
A while ago i noticed that /var partition on a certain server was almost filled up to a 100% up and started researching what caused this. I noticed that log files in /var/log directory were not rotating. I decided to run the log rotation manually when i got this error “error: bad top line in […]
We all know CentOS – Community Enterprise Operating System as a linux distribution aiming at enterprise class community-supported computing platform. CentOS aims to be 100% compatible with it’s upstream source Red Hat Enterprise Linux (RHEL). CentOS 7 was released on 7 th of July 2014 (RHEL 7 on 10th of June 2014) and its brings some major differences from it’s […]
Zenoss is a free and open source monitoring solution similar to Nagios. It can be used to monitor all sorts of hardware and in case of failures sends out alerts to recipients. Zenoss Core provides a web interface that allows system administrators to monitor availability, inventory/configuration, performance, and events. Compared to Nagios (my personal opinion) Zenoss has alot higher […]
PostgreSQL is a database server. It is an object-relational database management system and it’s main purpose is to store data. PostgreSQL calls itself “The world’s most advanced open-source database”. It is a fact that MySQL and PostgreSQL are two most popular open-source relation database management systems (RDMS). It is up to you to choose the one you […]
OwnCloud is a free and open-source software which enables you to create a private “file-hosting” cloud. OwnCloud is similar to DropBox service with the diference of being free to download and install on your private server. Advantage of OwnCloud over DropBox is that it is private (you manage it yourself) and not limited (only limited by hard disk […]
If you are a linux system administrator one of the more important things to learn and to know is how to manage users and groups on linux systems. This guide will describe how to add, delete and modify users and groups (manage users and groups) on CentOS 6 linux (same applies to other linux distributions) […]
We all know Apache HTTP Server. Apache is de-facto web server on UNIX-like systems and is maintained by an open community of developers of the Apache Software Foundation. Apache HTTP Server is released under the Apache License and is an open-source software. The problem with Apache HTTP Server on CentOS and other RHEL based distros is, […]
Kickstart file is a great solution which enables you to automate installation of CentOS Linux, Red Hat Enterprise Linux and other Red Hat Linux derivates. Kickstart file is basically a single file containing answers to all the questions that you would normally be asked during a typical installation of your Linux system. Kickstart file can […]
Yum or Yellowdog Updater Modified is a command line package management solution for Linux systems using RPM‘s like Red Hat Enterprise Linux, CentOS Linux, Fedora,… We can use yum to search, install, remove and check for additional information about RPM packages available to our Linux system. Yum works with local or remote repositories which are […]
NFS is short for Network File System. NFS server allows you to share a filesystem from a computer on the network to other computers on the same network. NFS is a server/client oriented protocol so one computer acts as a server and other computers (clients) connect to it. We will install and configure Ubuntu NFS Server […]
Distributed Replicated Block Device is a great way to replicate filesystem over the network to another server or host. Distributed Replicated Block Device actually mirrors a whole block device over the network therefore it is often used for High Availability (HA) clusters. Distributed Replicated Block Device is actually a network based RAID 1. Distributed Replicated Block Device has […]
