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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 …

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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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RHEL 7 – How to configure the Fencing on Pacemaker ?

RHEL 7 STONITH

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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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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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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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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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 …

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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. …

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