Beginning with AIX 5.2, the Multiple Path I/O (MPIO) feature allows you to define alternate paths to a device for failover purposes. Failover is a path management algorithm that improves the reliability and availability of a device because the system automatically detects when one I/O path fails and re-routes I/O through an alternate path. All SCSI SCSD disk drives are automatically configured as MPIO devices. Other devices may be supported, providing the device driver is compatible with the AIX MPIO implementation.
MPIO is installed and configured as part of BOS installation. No further configuration is required, but you can add, remove, reconfigure, enable and disable devices or device paths using SMIT, Web-based System Manager, or the command line interface. The following commands help manage MPIO paths: