Recent Articles

How to Install Tomcat 8 on CentOS 7.0 (Multiple Instances)

Apache Tomcat is an open source web server and servlet container developed by the Apache Software Foundation. It implements the Java Servlet, JavaServer Pages (JSP), Java Unified Expression Language and Java WebSocket specifications from Sun Microsystems and provides a web server environment for Java code to run in. This article will guide you through the […]

July 22, 2014 | By
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25 Linux Interview Questions and Answers (Basic and Scenarios)

As the opportunities for linux jobs are increasing day by day , its very  adequate to start preparing for linux interviews. In this article we have presented, questions and answers in basic level and scenarios. More likely all questions are related to system administration. Basic Questions 1. What is initrd image and what is its […]

July 21, 2014 | By
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How to Install and Configure Nagios 4.0.7 on CentOS 7.0

Nagios is a system and network monitoring application that offers monitoring and alerting services for servers, switches, applications, and services. It alerts the users when things go wrong and alerts them a second time when the problem has been resolved. Nagios runs periodic checks on user-specified resources and services, it can be used to monitor […]

July 18, 2014 | By
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A Good Understanding of D-BUS - An IPC Mechanism in Linux

D-BUS is an IPC (inter-process communication) mechanism that helps applications communicate with each other. D-Bus  (Desktop  Bus)  is  a  simple  IPC,  developed  as  part  of  freedesktop  projects. It  provides  an  abstraction  layer  over  various  applications  to  expose  their  functionalities  and  possibilities.  If  you  want  to  utilise  some  feature  of  an  application  to  make  another  program  […]

July 16, 2014 | By
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Linux Smem Tool - Displays Memory Usage More Accurate

In a shared memory environment, which is a technique used by most operating systems, there is a challenge of counting the memory several times. This ends up giving users and system administrators inaccurate information on how physical memory is used. To solve this problem smem comes in very handy. Smem reports Unique Set Size (USS) […]

July 13, 2014 | By
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Linux slabtop command - Display Kernel Slab Cache Information

The Linux kernel needs to allocate memory for temporary objects such as task or device structures and inodes. The caching memory allocator manages caches of these types of objects. The modern Linux kernel implements this caching memory allocator to hold the caches called the slabs. Different types of slab caches are maintained by the slab […]

July 11, 2014 | By
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Linux Shell Script to Sync Directories Interactively

This script will sync two directories between two servers. Basically we are using rsync features to run this program. Script will interactively request to input below details. 1) Remote server name or ip 2) Remote system user name 3) Local directory to sync 4) Remote directory to sync to 5) Check user need to copy timestamp […]

July 10, 2014 | By
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Web-vmstat Tool - Show Vmstats in Chart / Graphical Mode

Today's applications are made on web-based form. This can be understand that web applications are easy to see on every devices. Since the trend of smartphones and tablets, the use of web based applications are increasing rapidly. On Linux system, we have vmstat tool to monitor Linux system resources such as CPU, Memory, I/O and […]

July 9, 2014 | By
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Linux chpasswd Command - Change Passwords in Bulk Mode

Creating users and managing passwords is one of the primary responsibilities of a system administrator. A good policy requires modification of passwords on regular intervals. But changing the passwords for a number of users with passwd command becomes difficult. In this article we provide a method to change the passwords in batch mode. 1. The […]

July 7, 2014 | By
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Linux Process Environment Explained for Beginners

Processes are fundamental to Linux operating system. In order to understand how a Linux process works, it's important to know about its environment. For example, things like how main() function is called, how command line arguments are passed to a program, how a program accesses environment variables, how a process is laid out in memory, […]

July 4, 2014 | By
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How to Install CentOS 7 Step by Step with Screenshots

Finally the much awaited CentOS 7 is out. CentOS (Community Enterprise Operating System) is forked from RedHat Linux, a Linux Distro fine tuned for servers. In this article you will learn how to install CentOS 7 in a few easy steps. Step 1: Download The ISO Image To get a copy of CentOS 7 download […]

July 2, 2014 | By
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30 Handy Commands to Manage Exim Mail Server

Exim is a message transfer agent (MTA) for use on Unix systems connected to the Internet. It is freely available under the terms of the GNU General Public Licence. In style it is similar to Smail 3, but its facilities are more general. There is a great deal of flexibility in the way mail can […]

June 30, 2014 | By
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18 Examples to Learn Iptable Rules On CentOS

Iptable is the administration tool for IPv4 packet filtering and NAT. Iptables is used to set up, maintain, and inspect the tables of IPv4 packet filter rules in the Linux kernel. Several different tables may be defined.Each table contains a number of built-in chains and may also contain user-defined chains.Each chain is a list of […]

June 27, 2014 | By
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Mosh Tool - An Alternative Option for SSH and How to Use It

For those who love to work remotely, must know about SSH. This protocol is widely used by system administrators. SSH is also available in all platforms like Linux, Unix, Microsoft Windows, and Macintosh. But today, we have Mosh as an alternative for SSH. What is Mosh Mosh is a remote-terminal protocol like SSH. As it’s […]

June 25, 2014 | By
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