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

MODIFY CU / CNTLUNIT
606 z/VM: CP Commands and Utilities Reference
Note: You cannot specify managed channel paths.
UNIT_Address nn
UNIT_Address nn-nn
UNITADD nn
UNITADD nn-nn
tells CP which unit addresses you want to add to or delete from this control
unit. The variable nn must be a 1- to 2-digit hexadecimal number between X'00'
and X'FF'.
ESCON
tells CP that this control unit uses the Enterprise Systems Connection (ESCON)
channel to control unit interface to transmit data through optical cables. Also,
specify ESCON for a control unit that connects to ESCON unswitched channels.
LINK_address aa
LINK_address ddaa
LINK_address *
Each link-address value you specify identifies a port on a destination switch
(ESCON or FICON director) to which the control unit is connected.
The LINK_address operand must be specified when one or more of the channel
paths to the control unit are switched paths; that is, when any of the paths
traverse an ESCON or FICON director and for an ESCON director the path
through the director is not dedicated. When all of the channel paths are
unswitched (including dedicated paths through an ESCON director), the
LINK_address operand is optional.
For an unswitched FICON channel path, the end nodes determine the link
addresses used at each end. Thus you cannot specify a numeric link address to
be used. If you specify a LINK_address operand value for an unswitched
FICON channel path (e.g., because other paths to the control unit are switched
and a ″placeholder″ value is required), you must specify an asterisk (*) as the
link-address value.
When any link addresses are required to be specified (i.e., when one or more of
the channel paths is a switched path), you must provide a link address for each
channel-path identifier (PATH or CHPID) that you specified, in the same order.
When no link addresses are required to be specified (i.e., when all of the
channel paths are unswitched paths), the link address for each ESCON channel
path is determined by the hardware processor, and the link address for each
FICON channel path is negotiated between the hardware endpoints.
The link address is a one or two digit hexadecimal value for control units
connected to an ESCON channel. The link address is a one, two, three, or four
digit hexadecimal value for control units connected to a FICON channel.
Leading zeroes can be omitted, except that an actual dd value of zero (see
below) must be specified with at least one digit.
aa is the one-byte port-area address in an ESCON or FICON director to which
the control unit is connected. This address must be a one or two digit
hexadecimal number between X’01’ and X’FE’ for ESCON directors, and
between X’00’ and X’FF’ for FICON directors.
Link addresses for channel paths having dedicated (unswitched) connections
through an ESCON director can be arbitrary within the above-specified range,
but it is recommended that the actual port-area address be used.
ddaa is the first two bytes of a standard three-byte fibre-channel port address.
The third byte of a standard port address is used for fibre-channel arbitrated
loops, which are not supported for FICON channels and therefore you do not