Linux

20 Zypper Command Examples to Manage Packages on SUSE Linux

by Karthikeyan Sadhasivam on April 13, 2015

SUSE Linux Logoyum is for CentOS and Redhat.

apt-get is for Debian and Ubuntu.

In the same way, zypper is for SUSE Linux.

Zypper is a command line tool for package management in OpenSUSE and SUSE Enterprise Linux platforms.
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How to Sync and Start Redhat Cluster to Verify Failover Scenario

by Karthikeyan Sadhasivam on March 19, 2015

In the first part, we explained in detail on how to install and configure 2 Node RedHat Cluster.

We covered the following high-level steps in the previous tutorial:

  • Install and start RICCI cluster service
  • Create cluster on active node
  • Add a node to cluster
  • Add fencing to cluster
  • Configure failover domain
  • Add resources to cluster

In this tutorial, we’ll cover the following high-level steps to finish the cluster setup:
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How to Configure Linux Cluster with 2 Nodes on RedHat and CentOS

by Karthikeyan Sadhasivam on March 18, 2015

In an active-standby Linux cluster configuration, all the critical services including IP, filesystem will failover from one node to another node in the cluster.

This tutorials explains in detail on how to create and configure two node redhat cluster using command line utilities.

The following are the high-level steps involved in configuring Linux cluster on Redhat or CentOS:
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How to Add Memory, vCPU, Hard Disk to Linux KVM Virtual Machine

by Karthikeyan Sadhasivam on February 10, 2015

In our previous article of Linux KVM series, we explained how to Install Linux KVM and create a Guest VM.

But, once you’ve created a Guest VM, you need to know how to perform some of the routine maintenance activities on the VM.

This tutorial will explain how to perform the following Linux KVM VM activities:

  1. Add Memory to VM
  2. Add vCPU to VM
  3. Add Disk to VM
  4. Save VM Configuration
  5. Delete a VM

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7 Steps to Build a RPM Package from Source on CentOS / RedHat

by Karthikeyan Sadhasivam on February 4, 2015

Sometimes you might have access to an open source application source code but might not have the RPM file to install it on your system.

In that situation, you can either compile the source code and install the application from source code, or build a RPM file from source code yourself, and use the RPM file to install the application.

There might also be a situation where you want to build a custom RPM package for the application that you developed.

This tutorial explains how to build a RPM package from the source code.
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12 CUPS lpadmin Command Examples to Setup Printers on Linux

by Karthikeyan Sadhasivam on January 12, 2015

CUPS stands for Common UNIX Printing System.

lpadmin is a command line tool used to configure printer and class queues provided by CUPS.

A system running CUPS is a host that can accept print jobs from client computers, process them, and send them to the appropriate printer. It can also be used to set the server default printer or class.

This tutorial explains how to add a new printer, setup printer options, and manage printers on Linux environment using lpadmin command examples.
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How Install and Configure OpenLDAP on CentOS / RHEL Linux

by Karthikeyan Sadhasivam on January 6, 2015

OpenLDAPLDAP stands for Lightweight Directory Access Protocol.

LDAP is a solution to access centrally stored information over network. This centrally stored information is organized in a directory that follows X.500 standard.

The information is stored and organized in a hierarchical manner and the advantage of this approach is that the information can be grouped into containers and clients can access these containers whenever needed.

The OpenLDAP hierarchy is almost similar to the DNS hierarchy.
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This tutorial explains the process of building useful multi­-part commands piece by piece.

To build complex commands in the terminal, we need to understand piping. Piping is basically taking the output of one command and sending it to another command as input. This is done with the | (pipe) symbol.

Last month, a small project required me to repeatedly read similar XML files to provide test data for another program. I would have to do it so frequently that it would be annoying to have to download, save, parse and repeat. The basic requirements were:
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