IBM PowerHA SystemMirror, formerly known as HACMP (High Availability Cluster Multiprocessing), is a high availability and disaster recovery solution designed for IBM Power Systems servers running AIX or IBM i operating systems. Let’s explore its history and features:

History of IBM PowerHA SystemMirror:
– IBM PowerHA SystemMirror has a long history, starting with the introduction of HACMP in the 1990s. HACMP was initially developed by a company called Tivoli Systems, which was later acquired by IBM.
– Over the years, IBM continued to enhance and expand the capabilities of HACMP, renaming it to PowerHA SystemMirror to align with the broader IBM Power Systems branding.
– PowerHA SystemMirror has been a key solution for providing high availability and disaster recovery capabilities on IBM Power Systems, catering to the mission-critical requirements of enterprise environments.

Features of IBM PowerHA SystemMirror:
1. High Availability: PowerHA SystemMirror ensures high availability by providing automated failover and recovery capabilities. It monitors the health of critical resources, such as applications, databases, and services, and automatically switches to a backup server in case of a failure.
2. Continuous Application Availability: PowerHA SystemMirror enables applications to remain available during planned or unplanned outages. It facilitates seamless failover, minimizing downtime and disruption to users.
3. Geographic Redundancy and Disaster Recovery: PowerHA SystemMirror supports disaster recovery scenarios by providing synchronous or asynchronous replication of data across geographically dispersed sites. This allows for quick recovery in the event of a site failure or disaster.
4. Cluster Management: PowerHA SystemMirror provides centralized cluster management and configuration. It offers a graphical user interface (GUI) and command-line interface (CLI) for simplified administration and monitoring of the cluster environment.
5. Resource Monitoring and Failover Control: PowerHA SystemMirror monitors the health and status of resources, such as network interfaces, storage, and applications. It automatically triggers failover in case of resource failures, ensuring uninterrupted service availability.
6. Scalability and Flexibility: PowerHA SystemMirror supports both two-node and multi-node cluster configurations, allowing scalability based on business requirements. It can be easily configured to accommodate changes in the cluster environment, such as adding or removing nodes or resources.
7. Integration with Storage Solutions: PowerHA SystemMirror integrates with IBM storage solutions, such as IBM SAN Volume Controller (SVC) and IBM Spectrum Virtualize, enabling seamless replication and data consistency across storage systems.
8. Concurrent Maintenance: PowerHA SystemMirror supports concurrent maintenance, allowing for planned hardware or software upgrades without disrupting the availability of critical applications. It ensures uninterrupted service while performing maintenance tasks.
9. Application-Awareness: PowerHA SystemMirror provides application-awareness through resource agents, allowing administrators to define specific behaviors and requirements for different applications during failover and recovery processes.
10. Continuous Improvement and Support: IBM PowerHA SystemMirror is continually enhanced by IBM, with regular updates, patches, and new features being released. IBM provides comprehensive technical support and documentation to assist users in deploying and managing the solution effectively.

IBM PowerHA SystemMirror is a robust and mature high availability and disaster recovery solution for IBM Power Systems. Its features cater to the demands of enterprise environments, ensuring continuous application availability, data integrity, and disaster recovery capabilities.