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

Usage Notes
CSS nn
is the channel-subsystem ID of the specified channel paths. The variable nn
must be a 1- to 2-digit hexadecimal number between X'00' and X'0F'. See
Usage Note 6.
Note: This parameter and other parameters that identify different
channel-subsystem IDs require the logical channel-subsystem facility to
be installed.
MANaged_paths n
is the maximum number of managed channel paths that can be attached to the
specified control unit. The variable n must be a 1-digit decimal number from 1
to 7.
Note: The actual managed paths cannot be specified in the control-unit
definition; only the maximum number of managed channel paths can be
specified. The managed paths will be associated with specific control
units automatically by z/OS’s dynamic-channel-path-management
function. When a maximum number of managed paths is specified, the
channel paths named in the CHPID/PATH operand must all be shared
and of the type CNC, FC, or FCV. Also, the number of paths specified
with the CHPID/PATH operand when added to the maximum number of
managed paths specified cannot exceed 8.
1. Devices attached to your system communicate with the system through control
units and channel paths. Thus, before you dynamically define a new device to
your system, you must first dynamically define one or more control units for that
device (if they do not already exist) and one or more channel paths (if they do
not already exist).
If you need to physically define any channel paths, control units, or devices, use
the following commands in the following order:
a. To define channel paths, use the DEFINE CHPID or PATH command. (See
page 124.)
b. To define control units, use the DEFINE CU or CNTLUNIT command.
c. To define devices, use the DEFINE DEVICE or IODEVICE command. (See
page 155.)
If you do not define the channel paths, control units, and devices correctly and
in the proper order, CP will issue appropriate error messages.
2. After successfully entering this command, you will have changed the software’s
view of the I/O configuration and part of the hardware’s view: the active I/O
configuration in the hardware system area (HSA). You should also change the
other part of the hardware’s view: the active I/O configuration data set (IOCDS)
file on the support element (SE) hard disk.
To change the IOCDS file on the SE hard disk, you must:
a. Update the IOCP source file.
DEFINE CU / CNTLUNIT
b. Run the IOCP utility (see page 1849) against the updated IOCP file. 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 (see page 1258) to make the new
IOCDS file the active file that the processor will use during the next
power-on reset (POR).
Chapter 2. CP Commands 153