Cable Lengths And Types For Escon Adapters On Zseries Hosts; Logical Paths And Path Groups For Escon Adapters On Zseries Hosts; Data Transfer For Escon Adapters On Zseries Hosts; Directors And Channel Extenders For Escon Adapters On Zseries Hosts - HP XP20000/XP24000 Operation Manual

NOTE:
For optimum performance, use a cable shorter than 103 km (64 mi). An ESCON host channel can
connect to more than one storage unit port through an ESCON director.
The S/390 or zSeries host system attaches to one port of an ESCON host adapter in the storage unit.
Each storage unit adapter card has two ports. For the XP24000/XP20000 disk array, each ExSA
has 4 ports per adapter card and 8 per pair.

Cable lengths and types for ESCON adapters on zSeries hosts

The cable that is attached to the host adapter can be up to 2 km (1.24 mi) in length using 50-μm fibre
or 3 km (1.86 mi) in length for 62.5-μm fibre. This cable is used to make the connection between the
following components:
Host channel controller v Peer controller host channel
Peer controller with appropriate equipment
NOTE:
Appropriate retention hardware to support cable attachments that control bend-radius limits comes
with each ESCON host attachment.

Logical paths and path groups for ESCON adapters on zSeries hosts

Each ESCON adapter card supports two ESCON ports or links. Each port supports 64 logical paths.
At the maximum of 32 ESCON ports, the number of logical paths is 2048. Each controller image
supports up to 64 path groups. Each path group might have up to eight logical paths. Each controller
image supports a maximum of 512 logical paths per control unit image.

Data transfer for ESCON adapters on zSeries hosts

The ESCON host adapter supports all data input buffer sizes up to 256 bytes. During write operations,
the host adapter requests the minimum hexadecimal pacing count of X'02'. For commands whose
parameter data length is not determined by the parameter data itself, the full transfer count in the
command frame is requested in the first data request. The adapter supports an NDF-R count of 7 (that
is, a maximum of eight data requests).

Directors and channel extenders for ESCON adapters on zSeries hosts

The storage system supports IBM ESCON directors 9032 Models 1, 2, 3, and 5. The storage system
also supports IBM 9036 channel extenders to the distances that are allowed by the 9036 as described
in "Cable lengths and types for ESCON adapters on zSeries hosts". The storage unit supports the
9729 Wavelength Division Multiplexer channel extender up to 50 km (31 mi).

Identifying the port for TSO commands on zSeries hosts

You can use the devserv command to identify ports on a zSeries or S/390 host. This command is
used to identify the port ID for the MVS TSO commands for S/390 and zSeries hosts. Numbers such
as 806, 804, 802, and 800 are internal microcode numbers. Numbers such as 00, 04, 08, and 0C
XP Disk Array Mainframe Host Attachment and Operations Guide 13