Introduction to Oracle KVM Cluster
Oracle KVM Cluster is an enterprise-grade virtualization solution that leverages the Kernel-based Virtual Machine (KVM) hypervisor, integrated within Oracle Linux. It enables the creation and management of clustered virtual environments, providing high availability, scalability, and centralized management for virtual machines across multiple physical hosts. By combining the performance and efficiency of KVM with Oracle's robust clustering and management tools—such as Oracle Linux Virtualization Manager (OLVM) and Oracle Clusterware—Oracle KVM Cluster supports mission-critical workloads with features like live migration, fault tolerance, and resource pooling. This makes it an ideal platform for consolidating workloads, optimizing resource utilization, and ensuring business continuity in modern data centers.
In this blogpost we will see how we can configure the KVM cluster using the command Line options:
Creating an Oracle KVM cluster from the command line with hosts kvmhost1, kvmhost2, and kvmhost3 involves several steps, including installing required packages, configuring the cluster software, and setting up fencing. Here's a concise guide using pcs (Pacemaker/Corosync stack), which is the standard in Oracle Linux for clustering.
Prerequisites
Ensure the following on all three hosts:
Oracle Linux 8 or 9
Hostnames and /etc/hosts properly set
Time synchronized (e.g., via chronyd)
Passwordless SSH (or same root password if using pcs cluster auth)
Required packages installed
Step-by-Step: Oracle KVM Cluster from CLI:
1. Install Cluster Packages:
On all hosts:
2. Authenticate Cluster Nodes
On any one node:
dnf install -y pacemaker pcs fence-agents-all systemctl enable --now pcsd echo "yourpassword" | passwd --stdin hacluster
pcs host auth kvmhost1 kvmhost2 kvmhost3 -u hacluster -p yourpassword3. Create the Cluster On the same node:
pcs cluster setup --name kvmcluster kvmhost1 kvmhost2 kvmhost34. Start the Cluster
pcs status5. Verify Cluster Status
pcs statusTest Your Cluster
- Stop one node: systemctl stop pacemaker
- Watch failover and resource relocation: pcs status
Conclusion:
Configuring a KVM cluster from the command line provides a powerful, flexible, and scriptable approach to building high-availability virtualization environments. Using tools like pcs and pacemaker, administrators can efficiently set up and manage multi-node clusters without relying on graphical interfaces, ensuring consistency and control across all hosts. This command-line method is particularly valuable for automation, remote deployments, and integration into larger DevOps workflows. With proper configuration—including fencing, resource management, and monitoring—a KVM cluster delivers resilient virtual machine hosting suitable for enterprise workloads.
Thanks for reading :)
BR,
ZAHEER
Comments