80 IBM eServer zSeries 900 Technical Guide
one of the CF LPs, while the other ICP is defined as shared by the operating system LPs
and the other CF LP. Both of these examples best exploit the peer capabilities of these
coupling channels by using the sending and receiving buffers of both channels.
򐂰 Each IQD CHPID represents one internal LAN. If you have no requirement to separate
LAN traffic between your applications, only one IQD CHPID needs to be defined in the
configuration.
Careful review of new CHPID numbers as a result of subsequent upgrades is required to
ensure Internal Coupling-3 channel and HiperSocket (iQDIO) CHPIDs don't conflict with the
new channels.
If an Internal Coupling-3 channel or HiperSocket (iQDIO) CHPID is defined where a real
channel is installed, the IC-3 channel or HiperSocket (iQDIO) CHPID will be placed in
definition error after a Power-On-Reset and will be unusable. Also, if an IC-3 channel or
HiperSocket (iQDIO) CHPID is defined to a CHPID number scheduled to be used for an MES,
the (concurrent) upgrade will
not install the new I/O features using the CHPID numbers
predicted in the CHPID Report from the upgrade order.
3.1.5 Enhanced Multiple Image Facility
The Enhanced Multiple Image Facility (EMIF) enables channel sharing among Processor
Resource/Systems Manager (PR/SM) logical partitions running on the z900 server.
With EMIF, multiple logical partitions can directly share channels and optionally share any of
the control units and associated I/O devices configured to these shared channels.
Enhancements to the Channel Subsystem allow the CSS to be operated as multiple logical
CSSs when the zSeries server is operating in LPAR mode so that one logical CSS is
automatically configured to each logical partition. Multiple Image Facility also provides a way
to limit the logical partitions that can access a reconfigurable channel or a shared channel to
enhance security.
With Multiple Image Facility, the CSS provides an independent set of I/O controls for each
logical partition called a CSS image. Each logical partition is configured to a separate CSS
image in order to allow the I/O activity associated with each logical partition to be processed
independently, as if each logical partition had a separate CSS. For example, each CSS image
provides a separate channel image and associated channel path controls for each shared
channel and separate subchannel images for each shared device that is configured to a
shared channel.
With Multiple Image Facility, you can configure channels as follows:
򐂰 ESCON (TYPE=CNC or TYPE=CTC)
򐂰 FICON (TYPE=FCV or TYPE=FC), Fibre Channel Protocol for SCSI (TYPE=FCP)
򐂰 InterSystem Coupling-3 peer (TYPE=CFP), InterSystem Coupling-3 compatibility mode
sender (TYPE=CFS), Integrated Cluster Bus-3 peer (TYPE=CBP), Integrated Cluster
Bus-2 sender (TYPE=CBS), Internal Coupling-3 peer (TYPE=ICP)
򐂰 HiperSockets (TYPE=IQD)
򐂰 Open Systems Adapter-2 (TYPE=OSA)
򐂰 OSA-Express (TYPE=OSD or OSE)
You can configure the channel path of these channel types in three ways:
1. An unshared dedicated channel path to a single logical partition

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