Escon Connectivity On Zseries Hosts; Host Adapters, Cables, Distances, And Specifications For Escon Adapters On Zseries Hosts - HP XP20000/XP24000 Operation Manual

For zSeries host attachment using ESCON, only the first 16 addresses of the LSSs can be used. The
ranges of supported device addresses may be noncontiguous. Devices that are not mapped to a
logical device respond and show address exceptions.
When a primary controller connects to a secondary controller, the primary connection converts to a
channel. The controller images can handle ESCON interconnections as follows:
1 - 256 devices (bases and aliases) per controller image
1 - 4,096 devices (bases and aliases) with 16 controller images
1 - 512 logical paths per controller image v 1 - 64 logical paths per ESCON port (shared by all
controller images)
256 path groups per control unit ImageHost HPF, cables, distances, and specifications for ESCON
adapters on zSeries hosts
Using ESCON adapters, the storage unit provides the following configurations:
A maximum of 64 host ports
A maximum of 64 logical paths per port to 16 control-unit images (4096 CKD devices) over a
single ESCON port on the storage unit
Zero to 64 ESCON channels, two per ESCON host adapter
Two ESCON links with each link that supports up to 64 logical paths
Up to 16 host adapters that provide a maximum of 32 ESCON links per machine
Up to 32 host adapters providing a maximum of 64 ESCON links per machine
NOTE:
ESCON host channels limit the number of devices per channel to 1024. To fully access 4096 devices
on a storage unit, it is necessary to connect a minimum of four ESCON host channels to the storage
unit. You can access the devices through a switch to a single storage unit ESCON port. This method
exposes four control-unit images (1024 devices) to each host channel.

ESCON connectivity on zSeries hosts

This describes how to attach a storage unit with ESCON adapters.
XP disk array storage units can be attached through ESCON links to different central-electronic
complexes and LPARs.
For optimum availability, you can make the ESCON host adapters available through all bays and
spread the connections to any single host across both clusters. For optimum performance, you can
have at least eight host adapter ports installed on four ESCON host adapter cards in the storage unit.
This setup ensures the best performance from the attached systems.

Host Adapters, cables, distances, and specifications for ESCON adapters on zSeries hosts

A storage unit emulates 0 through 16 of the logical controllers. The logical controllers are typically
split between 2 clusters. Because the ESCON adapter connects to both clusters, each adapter can
address 16 logical controllers.
Each ESCON host adapter provides two host connections. This requires two ESCON cables for each
adapter for S/390 and zSeries hosts. The maximum standard distance for ESCON cables is 2 km
(1.2 mi) with 50-μm multimode fibre and 3 km (1.9 mi) with 62.5-μm multimode fibre. This distance
can be extended 103 km (64 mi).
12 FICON/zHPF and ESCON host attachment