AIX high availability data path failover and dynamic load balancing

AIX® high availability data path failover and dynamic load balancing.

AIX high availability data path failover is designed to provide a failover mechanism in the AIX Atape device driver. This design enables the configuration of multiple redundant paths in a SAN environment with the 3592 tape drive. In a path or component failure, the failover mechanism is designed to automatically provide error recovery. It retries the current operation with an alternate, preconfigured path without stopping the current job in progress. This feature allows flexibility in SAN configuration, availability, and management.

A function in the AIX Atape device driver, Dynamic Load Balancing, is also available for the 3592 tape drives that are used in an AIX SAN environment. The dynamic load balancing support is designed to optimize resources for devices that have physical connections to multiple host bus adapters (HBA) in the same machine. When an application opens a device that has multiple configured HBA paths, the device driver determines which path has the HBA with the lowest usage, and assigns that path to the application. The device driver is designed to dynamically track the usage on each HBA as applications open and close devices, and balance the number of applications with each HBA in the machine. This procedure can help optimize HBA resources and improves overall performance. For information, see the IBM® Tape Device Drivers Installation and User's Guide, GC35-0154, available at the IBM Fix Central website.