IBM EXP15, Руководство по техническому обслуживанию аппаратной части

Страница: 104 / 146

Netfinity FAStT EXP500 loop redundancy:
The
Netfinity FAStT EXP500 expansion unit provides redundant
loop support. This redundant loop support is available
when the second ESM board is configured (as shown in
the figure below). If an ESM board, cable, or GBIC fails
on a loop, the second loop provides an additional measure
of redundancy (that is, an alternative path to your disk
drives).
Some FC controllers might not support loop redundancy.
IBM Fibre Channel (FC) disk drives are dual-ported,
providing individual access from two FC loops to the same
disk drive. When configuring the ESM boards, configure
the second ESM board the same way you configured the
first ESM board. Refer to your controller documentation
for more information on dual-loop support and
implementation.
Loop B
interface
cable
Input Output
ESM board CRU
The GBIC ports are labeled with an (input) and an
(output). Some controllers might provide additional
reliability features if an (input) port is connected to an
(output) port. As you daisy-chain Netfinity FAStT EXP500
expansion units together, connecting (input) ports to
(output) ports can facilitate reliability. In many cases, a
loop will still function properly without attaching the
(input) ports to (output) ports. Refer to your controller
documentation for requirements on connections between
input and output ports.
A lit Bypass indicator next to a GBIC can be caused by a
number of things. It does not necessarily mean that the
GBIC has failed. Refer to “Symptom-to-FRU Index” on
page 71 for other possible causes. If you do determine
that a GBIC has failed, follow the procedures below to
replace the failed GBIC.
1. Check the software documentation provided with your
system for instructions on GBIC failure recovery
96
IBM Netfinity EXP15, EXP200, EXP500 HMM