Home / Redhat-LINUX


Configuring NFS HA using Redhat Cluster – Pacemaker on RHEL 7

NFS HA - Pacemaker UnixArena

This article will help you to setup High Availability NFS server using Pacemaker on Redhat Enterprise Linux 7. From the scratch ,we will build the pacemaker blocks which includes package installation , configuring the HA resources, fencing etc. NFS shares are used for setting up the home directories and sharing the same content across multiple servers. NFS HA will suit …

Read More »

Let’s Start exploring the Docker – Container World

hypervisor - Vmware vs Docker

Virtualization industry is bringing up many interesting and yet useful products in the market to reduce the IT cost.  VMware revolution demonstrated that how to utilize  the hardware effectively using hypervisor and other sibling products.  Similarly openstack development also going on aggressive pace to reduce the virtualization product cost by utilizing  opensource technologies. Docker was no where in the competition but …

Read More »

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” …

Read More »

RHEL 7 – Pacemaker – Cluster Resources/Group Management – Part 6

RHEL 7 cluster Resource group

In Pacemaker/Corosync  cluster (RHEL 7 HA),  resources management and resource group management are important tasks . Depends on the cluster HA services, you might need to configure N-number of resources. In most of the cases , you might need to start set of resources sequentially, and stop in the reverse order.  To simplify this configuration, Pacemaker supports the concept of groups (Resource …

Read More »

RHEL 7 – Pacemaker – Cluster Resource Agents Overview – Part 5

Pacemaker resource agents

Resource agents plays an important role in cluster management.  Resource agents are multi-threaded processes that provides the logic to manage  the resources. Pacemaker has one agent per resource type. Resource type could be a File-system , IP address , databases, virtual-domain and more. Resource agent is responsible to monitor, start , stop,validate , migrate , promote and demote  the cluster resources whenever required. …

Read More »

RHEL 7 – Configuring Pacemaker/Corosync – Redhat Cluster – Part 4

Redhat cluster - pacemaker corosync configuration

In this article, we will see that how to configure two node Redhat cluster using pacemaker & corosync on REHL 7.2. Once you have installed the necessary packages, you need to enable the cluster services at the system start-up. You must start the necessary cluster services before kicking off the cluster configuration. “hacluster” user will be created automatically during the package …

Read More »

RHEL 7 – Installing Redhat Cluster Software (Corosync/pacemaker) – Part 3

Redhat Cluster 7 - RHEL 7 - Pacemaker installation

In this article, we will see that how to install Redhat cluster software (Pacemaker) on RHEL 7. If you have valid redhat subscription , you can directly configure redhat repository and install the packages. It also available in the RHEL 7 ISO image as an Add-on Package. Unlike previous redhat cluster releases , Redhat cluster 7 installation looks very simple since redhat has …

Read More »

Linux KVM – Change libvirt VM image store path – Part 10

Libvirt Image location - KVM

In KVM , VM images are stored in /var/lib/libvirt/images directory by default.  There might be the space limitation since /var filesystem lives under root-vg. In KVM virtualization, everyone would prefer to store VM images in central repository to migrate running VM from one hypervisor to another.  In that case, you need to change the default path for the libvirt images or  you need to mount …

Read More »