z/VM: CP Commands and Utilities Reference - z/VM - IBM

Responses
Messages
configuration file, or some combination thereof. After initialization, you can
change the software’s view of the I/O configuration using the SET RDEVICE
command (page 1333) or the dynamic I/O commands listed in Usage Note 3 on
page 1258.
The hardware creates its view of the I/O configuration at power-on reset (POR)
time. The I/O configuration is defined in the I/O configuration program (IOCP)
source file that is stored on a user’s minidisk (or SFS directory). You run the
IOCP utility against the IOCP source file to create an I/O configuration data set
(IOCDS) file that is stored on the support element (SE) hard disk. You can have
multiple IOCDS files stored on the SE hard disk. At power-on reset time, you
choose the IOCDS file that you want to use. The specified IOCDS file is copied
to the hardware system area (HSA) storage and becomes the active hardware
I/O configuration. Thus, there are 2 parts to the hardware’s view of the I/O
configuration: the active IOCDS file in HSA storage and the IOCDS file on the
SE hard disk.
After the machine is up and running, you can change the hardware’s view of the
active I/O configuration using the dynamic I/O commands listed in Usage Note 3
on page 1258. However, these commands only change the active I/O
configuration in the HSA. They do not change the IOCDS file on the SE hard
disk.
To change the IOCDS file on the SE hard disk, you must:
a. Update the IOCP source file.
b. Run the IOCP utility (page 1849)against the updated IOCP file. Specify all
options you normally specify including WRTxx (to write the newly generated
IOCDS file to the SE hard disk) and DYN (to define the hardware
configuration token). If the IOCP utility runs without errors, it downloads the
new IOCDS file to the SE hard disk.
c. Issue the SET IOCDS_ACTIVE command to make the new IOCDS file the
active file that the processor will use during the next power-on reset (POR).
Response 1:
To change the active IOCDS file to A3, enter the following:
set iocds_active a3
The active IOCDS file is now A3
Ready;
HCP026E Operand missing or invalid
HCP6812E Set IOCDS_active command failed with
return code nnnn
HCP6814E Command is not valid on this
processor
SET IOCDS_ACTIVE
Chapter 2. CP Commands 1259