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

Usage Notes
MODIFY CU / CNTLUNIT
specify. This two-byte form of the link address is required when the channel
path is a FICON channel path that traverses more than one FICON director to
reach any of the channel-path’s destination control units.
This means that if the channel path traverses more than one FICON director to
reach this control unit, a two-byte link address is required. In addition, if the
channel path traverses only one FICON director to reach this control unit, but
the same channel path traverses more than one FICON director to reach some
other control unit, a two-byte link address is required for that channel path in all
control-unit definitions in which the channel path appears. That is, once a
two-byte link address is required for any control unit on a channel path, a
two-byte link address is required for all control units on that channel path.
dd is the switch address (or domain identifier) of the destination FICON director
(i.e., the switch to which the control unit is directly connected), and aa is the
port-area address within that FICON director. The link address must be a three
to four digit hexadecimal number between X’0000’ and X’FFFF’.
One-byte and two-byte link addresses can be mixed within the LINK_address
operand, according to the requirements for each channel path. You can choose
to use a two byte link address when only a one byte address is required as
long as the FICON director is configured with the high-integrity attributes (see
the IOCP User’s Guide for more information).
CU_LOGICal_address nn
CUADD
is the logical address of the control unit that you are changing. The variable nn
must be a 1- to 2-digit hexadecimal number between X'00' and X'FE'. If omitted,
the default is X'00'.
TYpe CF
tells CP that this control unit is connected to coupling facility channel paths.
Coupling facility channel paths include coupling facility sender (CFS), coupling
facility receiver (CFR), coupling facility peer (CFP), cluster bus sender (CBS),
cluster bus receiver (CBR), cluster bus peer (CBP), or internal coupling peer
(ICP) channel paths.
RCSS nn
is the reference channel-subsystem image from which the control unit attributes
are to be copied for the specified coupling-facility control unit that is being
added to the additional channel-subsystem image specified by the CSS nn
parameter. The variable nn must be a 1- to 2-digit hexadecimal number
between X'00' and X'0F'.
1. On a machine with multiple logical channel-subsystem images, the DEFINE CU
and DEFINE CNTLUNIT commands first define the control unit on channel
paths within the single specified channel-subsystem image. If the control unit is
connected to channel paths in more than one channel-subsystem image, then
MODIFY CU or MODIFY CNTLUNIT commands must be entered to define the
control unit’s connections to each group of channel paths in the additional
channel-subsystem images.
2. On a machine with multiple logical channel-subsystem images, the DELETE CU
and DELETE CNTLUNIT commands are effective only for control units in a
single channel-subsystem image. To delete control units that are in more than
one channel susbystem image, you must first enter MODIFY CU or MODIFY
CNTLUNIT commands to remove all but one channel-subsystem image. Then a
DELETE CU or DELETE CNTLUNIT command can be entered.
Chapter 2. CP Commands 607