92 IBM eServer zSeries 900 Technical Guide
Enhanced Multiple Image Facility
The Enhanced Multiple Image Facility (EMIF) enables ESCON channel sharing among
PR/SM logical partitions running on the z900 server. For details, see “Enhanced Multiple
Image Facility” on page 80.
3.3.1 Connectivity
Following are z900 connectivity options in the ESCON I/O interface environment.
z900 ESCON features
z900 supports two ESCON channel features: the 16-port ESCON feature (feature code
2323), and the 4-port ESCON feature (feature code 2313).
z900 16-port ESCON feature
The z900 16-port ESCON feature (feature code 2323) occupies one I/O slot in the z900
zSeries I/O cage. Each port on the feature uses a 1300 nanometer (nm) light-emitting diode
(LED) transceiver, designed to be connected to 62.5 micron multimode fiber optic cables only.
The feature has 16 ports with one CHPID associated with each port, up to a maximum of 15
active ESCON channels per feature. There is a minimum of one spare port per feature to
allow for channel sparing in the event of a failure of one of the other ports.
This is a dramatic increase in channel density compared to the G5/G6 servers (4 ESCON
channels per feature). This allows up to 256 ESCON channels to be populated in a single
z900 zSeries I/O cage compared with three G5/G6 I/O cages.
The 16-port ESCON feature is supported by the z900 Channel CHPID Assignment facility
described in “CHPID assignments” on page 76.
The16-port ESCON feature port utilizes a small form factor optical transceiver that supports a
new fiber optic connector called MT-RJ. The MT-RJ is an industry standard connector which
has a much smaller profile compared with the original ESCON Duplex connector. The MT-RJ
connector, combined with technology consolidation, allows for the much higher density
packaging implemented with the 16-port ESCON feature.
An MT-RJ/ESCON Conversion Kit (feature code 2325) supplies two 62.5 micron multimode
conversion kits. The conversion kit is two meters (6.5 feet) in length and is terminated at one
end with a MT-RJ connector and at the opposite end with an ESCON Duplex receptacle to
attach to the under floor cabling.
16-port ESCON channel port enablement
The 16-port ESCON feature channel cards are always installed in pairs. The 15 active ports
on each 16-port ESCON feature are activated in groups of four via Licensed Internal Code -
Control Code. Ports are activated equally across all installed 16-port ESCON features for high
availability.
Note: The z900 16-port ESCON feature does not support a multimode fiber optic cable
terminated with an ESCON Duplex connector.
However, 62.5 micron multimode ESCON Duplex jumper cables can be reused to
connect to the 16-port ESCON feature. This is done by installing an MT-RJ/ESCON
Conversion kit between the 16-port ESCON feature MT-RJ port and the ESCON
Duplex jumper cable. This protects the investment in the existing ESCON Duplex
cabling plant.
Chapter 3. Connectivity 93
In most cases, the number of physically installed channels is greater than the number of
active channels that are LIC-CC enabled. This is not only because the last ESCON port (J15)
of every 16-port ESCON channel card is a spare, but also because several physically
installed channels are typically inactive (LIC-CC protected). These inactive channel ports are
used to satisfy future channel adds; see Table 3-7 on page 94 for details.
If there is a requirement to increase the number of ESCON channel ports (minimum
increment is four), and there are sufficient unused ports already available to fulfill this
requirement, then IBM manufacturing provides an LIC-CC diskette to concurrently enable the
number of additional ESCON ports ordered. This is illustrated in Figure 3-7. In this case, no
additional hardware is installed.
Figure 3-7 16-port ESCON - LIC-CC
An ESCON channel add will never activate the spare channel port. However, if the spare port
on a card was previously used, then the add may activate all the remaining ports on that card.
If there are not enough inactive ports on existing 16-port ESCON cards installed to satisfy the
additional channel order, then IBM manufacturing ships additional 16-port ESCON channel
cards (minimum of two) and an LIC-CC diskette.
If there has been multiple sparing on a 16-port ESCON card and, by replacing that card the
additional channel add can be satisfied, the card will be replaced.
Table 3-7 documents some ESCON configuration examples and details the way active and
inactive ESCON channel ports are spread over the installed 16-port ESCON cards.
A maximum of 256 ESCON ports can be activated on z900 server general purpose models.
This maximum requires eighteen 16-port ESCON channel cards to be installed.
LICCC ENABLEMENT
ESCON-16
J00
J01
J02
J03
J04
J05
J06
J07
J08
J09
J10
J11
J12
J13
J14
J15
ESCON-16
SPARE
CHANNEL
J00
J01
J02
J03
J04
J05
J06
J07
J08
J09
J10
J11
J12
J13
J14
J15
35
57
BF
20
ESCON-16
J00
J01
J02
J03
J04
J05
J06
J07
J08
J09
J10
J11
J12
J13
J14
J15
ESCON-16
SPARE
CHANNEL
J00
J01
J02
J03
J04
J05
J06
J07
J08
J09
J10
J11
J12
J13
J14
J15
35
57
BF
20
25
6E
8A
78
A
D
D
4
E
S
C
O
N
C
h
a
n
n
e
l
s
CHPID
Number
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