Recent Posts

February, 2016

  • 2 February

    Puppet – How to install and configure Puppet Enterprise (Master) ?

    This article is going to brief about the Puppet Server – Enterprise installation and configuration. We are going to install the puppet server  in monolithic mode. In monolithic installation, Puppet Master , Puppet console , Puppet DB will be installing on one node. This is the simple method to evaluate puppet enterprise and you can manage up to 500 puppet agent nodes. To know more about …

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January, 2016

  • 31 January

    Puppet – Configuration Management Software – Overview

    Large Split Installation

    Puppet  is an open-source configuration management / IT automation software that allows system administrators to programmatically provision, configure, and manage servers, network devices, and storage, in a datacenter or in the cloud. Puppet is written on RUBY language and it is produced by Puppet Labs.  Configuration Management tools uses either push or pull methods. Puppet uses pull method. In this method, puppet agents …

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  • 22 January

    RHEL7 – Configuring GFS2 on Pacemaker/Corosync Cluster

    GFS2 - RHEL 7

    This article will briefly explains about configuring the GFS2 filesystem between two cluster nodes. As you know that GFS2 is cluster filesystem and it can be mounted on more than one server at a time . Since multiple servers can mount the same filesystem, it uses the DLM (Dynamic Lock Manager) to prevent the data corruption. GFS2 requires a cluster suite …

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  • 21 January

    RHEL 7 – How to configure the Fencing on Pacemaker ?


    Fencing (STONITH) is an important mechanism in cluster to avoid the data corruption on shared storage. It also helps to bring the cluster into the known state when there is a split brain occurs between the nodes. Cluster nodes talks to each other over communication channels, which are typically standard network connections, such as Ethernet. Each resources and nodes have “state” …

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  • 14 January

    RHEL 7 – Accessing the Pacemaker WEB UI (GUI) – Part 11

    Add the pacemaker cluster to Web UI

    Pacemaker offers web based user interface portal to manage the cluster. It also provides an interface to manage multiple clusters in single web UI. We can’t really say that WEB UI has all the options to manage the cluster. I would say that command line is much easier and simple when you compare to GUI. However , you could give a try …

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  • 13 January

    RHEL 7 – Pacemaker – Configure Redundant Corosync Links on Fly– Part 10

    Corosync Links - RHEL7

    Corosync cluster engine provides the reliable inter-cluster communications between the cluster nodes. It syncs the cluster configuration across the cluster nodes all the time. It also maintains the cluster membership and notifies when quorum is achieved or lost. It provides the messaging layer inside the cluster to manage the system and resource availability. In Veritas cluster , this functionality has been provided by LLT + …

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  • 12 January

    RHEL 7 – Pacemaker – Define the Resource Behaviour – Part 9

    Pacemaker resource agents

    In Pacemaker/Corosync cluster, there are may aspects/key elements that we need to understand before playing with cluster operations. Otherwise , it might cause unnecessary outage/downtime for the services. The most important elements are setting the preferred resource location , ordering (defining dependencies) , resource fail counts, resource-stickiness, colocation, clone, master/slave, promote/demote etc. Let’s go through the article and understand how these elements contributes …

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  • 10 January

    RHEL 7 – Pacemaker – Cluster Node Management – Part 8

    Redhat Cluster with Pacemaker

    This article will demonstrates about the Pacemaker/Corosync cluster membership, node management and other  cluster operational tasks. Periodically , you might need to take the cluster node offline to perform the maintenance activities like OS package update/upgrade , hardware replacement/upgrade etc. In  such cases ,you need to put the cluster node in to standby mode to keep the cluster operational on other node …

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