Configuring and unconfiguring path failover support

Path failover support is not enabled automatically when the device driver is installed. It must be configured initially on each logical device after installation. When path failover support is enabled for a logical device, it remains set until the device is deleted or the support is unconfigured. The path failover setting is retained even if the system is rebooted.

Path failover support can be enabled on all configured devices at one time, or it can be enabled or disabled selectively by logical device. It might be desirable at times to configure some, but not all, logical paths to a device with the support enabled.

To enable the support globally on all currently configured devices, run the command
/usr/lpp/Atape/instAtape -a

This action unconfigures all devices that have path failover set to No, and reconfigures all devices, setting path failover to Yes.

To enable or disable the support on a single logical device, use the SMIT menu to Change/Show Characteristics of a Tape Drive, then select Yes or No for Enable Path Failover Support. The support can also be enabled or disabled by using the chdev command, for example:
chdev -l rmt0 -aalt_pathing=yes

chdev -l rmt0 -aalt_pathing=no