IBM High Availability Cluster Multiprocessing
| Company type | Software |
|---|---|
| Industry | Information technology |
| Predecessor | HACMP |
| Founded | 1991 |
| Products | Clustering software for high availability on AIX Unix and Linux environments |
| Owner | IBM |
IBM PowerHA SystemMirror—previously known as IBM PowerHA and HACMP—is IBM’s clustering software designed to ensure high availability on AIX Unix and Linux environments running on IBM System p hardware. Initially introduced in 1991 under the name HACMP, the product has evolved through 20 iterations, with the latest release being PowerHA SystemMirror for AIX 7.1.
This clustering solution accommodates up to 32 nodes within a cluster, where nodes can either actively host applications or remain on standby to assume control if another node fails. It also facilitates shared file system access throughout the cluster environment.
PowerHA SystemMirror is tightly integrated with IBM’s Reliable Scalable Cluster Technology (RSCT), which is included with AIX. RSCT manages cluster-related events such as failures of nodes or network interfaces through its group services daemon. Prior to the 7.1 release, RSCT’s topology services daemon (topsvcs) handled node and network monitoring. However, starting with version 7.1, these monitoring and communication responsibilities were shifted to the Cluster Aware AIX (CAA) framework.
Version 7.1 of PowerHA utilizes CAA, a native clustering infrastructure embedded within AIX that supports both RSCT and PowerHA functionalities. CAA provides monitoring, communication, and cluster-wide event notifications via components such as the Autonomic Health Advisor File System (AHAFS) and cluster-aware commands like clcmd, effectively replacing the previous topology services capabilities.
IBM PowerHA SystemMirror Releases
- PowerHA SystemMirror 7
- Version 7.2 debuted in October 2015
- Version 7.2.1 followed in October 2016, introducing a redesigned user interface along with streamlined migration assistance
- Version 7.1 released in 2010, built upon the Cluster Aware AIX (CAA) framework available in AIX V6.1 TL6 and AIX 7.1
- Version 7.1.1 arrived in February 2012
- Version 7.2 debuted in October 2015
- PowerHA 6
- Version 6.1 was rebranded as IBM PowerHA SystemMirror for AIX and became generally available in October 2009
- This release introduced Standard and Enterprise Editions
- Added support for EMC SRDF, a GLVM two-site Configuration Wizard, enhancements to SMIT panels, and IPv6 compatibility
- Version 6.1 was rebranded as IBM PowerHA SystemMirror for AIX and became generally available in October 2009
- HACMP 5
- Version 5.5 was renamed IBM PowerHA in November 2008
- Included asynchronous replication capabilities, improved DLPAR/CUOD support for POWER5 and POWER6 processors, and LPAR mobility for mission-critical workloads
- Integrated PowerHA/XD PPRC with Global Mirror and SAN Volume Controller; supported multiple storage arrays per site
- Enhanced AIX operating system integration by eliminating the need for TCP/IP process modifications
- Version 5.4.1 (November 2007) incorporated AIX Workload Partitions (WPAR), GLVM monitoring features, and improvements to NFSv4
- Version 5.4 (July 2006) introduced a web-based graphical user interface along with non-disruptive cluster startup and maintenance functions
- Previous releases include HACMP versions 5.3 (August 2005), 5.2 (July 2004), and 5.1 (July 2003)
- Version 5.5 was renamed IBM PowerHA in November 2008
- HACMP 4
- Versions include HACMP 4.5 (July 2002) and HACMP 4.4 (June 2000), alongside earlier editions that introduced key features such as Cluster Single Point of Control (CSPOC) and Dynamic Reconfiguration