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Changing active I/O software configuration for z/OS virtual server instances

The Hardware Configuration Definition (HCD) component of z/OS consolidates the hardware and software I/O configuration processes under a single interactive user interface. The output of HCD is an I/O definition file (IODF), which contains I/O configuration data. An IODF is used to define multiple software configurations to the z/OS virtual server instance. The IODF PROV.IODF00 exists in the z/OS stock image. The corresponding data sets are on volume OPEVS1 with device 0DE28.

If you want to change the active I/O configuration, you need to use one of the following methods to activate the IODF.

Note: z/OS stock images always IPL with LOADxx member LOADK2 found in SYS0.IPLPARM. The IODF statement identifies the I/O definition file that contains information about the I/O configuration, which means you need to specify the IODF statement so that the corresponding I/O configurations will be used at IPL. You must follow the IODF statement policies for the z/OS virtual server instance:

  • The IODF suffix is part of the IODF name. The range value is a two-digit hexadecimal number (X'00-FF').
  • Asterisks (**), pluses (++), minuses (--), and equals (=) in IODF suffix are not supported for z/OS virtual server instances.
  • The IODF high-level qualifier needs to be specified explicitly.
  • The subchannel set indicator needs to be specified as 0.
  • The specified IODF needs to reside on the IODF disk device 0DE28 with volume OPEVS1.

For more information, see Statements and parameters for LOADxx External link icon.