How to work with I/O Autoconfiguration

You can use the HCD I/O Autoconfiguration function to perform automatic configuration changes in order to define switched FICON connected or FICON directly connected DASD and tape control units and devices which are currently not yet defined in the base IODF, which can be either the active or currently accessed IODF. Proposed definitions are automatically written into a specified target work IODF which is created as a copy of the active or accessed IODF.

For I/O Autoconfiguration, HCD invokes the Input/Output Subsystem (IOS) to discover I/O hardware in the current configuration that is accessible to the system. HCD can define connections between processors and controllers through combinations of switch-attached paths and point-to-point paths. Proposed definitions are automatically written into a specified target work IODF which may be created as a copy of the active or accessed IODF. You can control the proposals for autoconfiguration changes by specifying autoconfiguration policies.

I/O Autoconfiguration is available starting with zEnterprise processors (processor type 2817). It requires the same access authorization as used for dynamic reconfiguration (see Giving users access authority).

During I/O Autoconfiguration processing, HCD presents the discovered controllers, control units and devices to the user and offers proposals how to configure them. The user can accept or change these definition proposals. On the user’s confirmation, the configuration definitions are then written into the specified target IODF.

HCD provides a series of dialogs to perform automatic I/O configuration:

1. A dialog to define autoconfiguration policies:

   Before you start the discovery processing, you can define the policies which control the automatic definition of discovered control units and devices.

   For more information, refer to How to define autoconfiguration policies.

2. A dialog to perform the discovery and definition process:

   You define the scope of discovery, select the autoconfiguration operation mode (attended or unattended fast-path mode), select the IODF against which the discovery should run and the target IODF that receives the resulting configuration definitions for all discovered new or changed controllers.

   After having defined or revised the mentioned options, you can invoke the discovery and definition processing. Depending on the selected operation mode, the dialog either leads you through the configuration steps or directly defines the discovered controllers and devices in the target IODF.

   For more information, refer to How to perform automatic I/O configuration.

Through determining the configuration characteristics of the discovered control unit as established at the controller side, and through establishing a recommended configuration based on availability and performance considerations, this functionality ensures that the controller configuration matches its logical definition.

After a successful run of I/O Autoconfiguration, you have complete update control regarding the I/O definitions written to the target IODF.