IBM Z9, Руководство по планированию

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Note: The following bulleted items only describe z/OS to coupling facility
connections. However, they also apply to coupling facility duplexing
connections (CF to CF).
Coupling facility channels:
v
Require a point-to-point connection (direct channel attach between a CPC or LP
and a coupling facility). Internal Coupling channels can only be used to connect a
coupling facility and LPs on the same CPC.
v Can be used to connect a coupling facility to other LPs on the same CPC when
a coupling facility is one of multiple LPs running on a single CPC. Internal
coupling channels should be used for these connections.
v
Can be redundantly configured (two or more coupling facility channels from each
CPC involved in coupling facility data sharing) to enhance availability and avoid
extended recovery time. This does not apply to Internal Coupling channels.
v Require ICP, CBP, CIB, or CFP channel path definition at the coupling facility end
of a coupling facility channel connection.
v
Require ICP, CBP, CIB, or CFP channel path definition at the z/OS (and, for
System-Managed CF Structure Duplexing, the coupling facility) end of a coupling
facility channel connection.
v
Require a CBP, CFP, CIB, or ICP channel path be connected to a CBP, CFP,
CIB, or ICP channel path, respectively. You must define the ICP channel paths in
pairs and you must connect each pair. You connect an ICP channel path to an
ICP channel path by specifying the CPATH keyword on the CHPID statement for
every ICP channel path.
Internal Coupling Channel
The Internal Coupling channel emulates the coupling facility functions in LIC
between images within a single system. Internal Coupling channel implementation is
totally logical requiring no channel or even cable hardware. However, a CHPID
number must be defined in the IOCDS. Internal Coupling channels cannot be used
for coupling connections to images in external systems.
Partitions with Internal Coupling channels can also have coupling facility channels
which allow external system coupling. ICs, which utilize the system bus, are
extremely fast (approximately 6 GB/second).
Internal Coupling channels will have channel path type of ICP (Internal Coupling
Peer). Internal Coupling channels are identified by 2 CHPIDs representing the two
ends of a coupling link. The rules that apply to the ICP CHPID type are the same
as those which apply to external coupling link types, with the exception that the
following functions are not supported:
v
Service On/Off
v
Reset I/O Interface
v Reset Error Thresholds
v Swap Channel Path
v CHPID Reassign
v Channel Diagnostic Monitor
v R/V
v Configuration Manager Vital Product Data (VPD)
Internal coupling channels have improved coupling performance over ICBs and
coupling facility channels.
Chapter 2. Planning Considerations
2-55
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