IBM SY33-0193-00 manual SSA Link Error Problem Determination, Example

SSA Link Errors

SSA link errors can be caused by a number reasons, for example if:

Ÿ Power is removed from an SSA device

Ÿ An SSA device is failing

Ÿ An SSA device is removed

ŸA cable is disconnected.

Errors might be indicated in various ways, such as:

ŸSRN 45PAA

Ÿ A flashing link status (Ready) light on the SSA device at each end of the faili

Ÿ The indication of an open link when using the Disk Service Aid.

SSA Link Error Problem Determination

Instead

of

using the

normal

MAPs to solve a link error

problem, you can refer direc

the

link

status

lights to isolate the failing FRU. The

descriptions

given

here show

how

to do

this.

In

an SSA loop, devices are connected through two or

more SSA links to an

SSA

RAID

Adapter. Each SSA link is the connection between two SSA

nodes (devices or

adapters);

for

example:

Ÿ

Disk drive to disk drive

Ÿ

Adapter to disk drive module

Ÿ

Adapter

to

adapter

An

SSA

link

can

contain several

parts. When doing problem

determination,

think

of

the

link

and

all

its

parts

as one

complete item.

Here are some examples of SSA links. Each link contains more than one part.

Example 1

This link is between two disk drives that are in the same subsystem. It has three

SSA Subsystem

Disk Internal Drive 1Connection

Disk

Drive 2

 Copyright IBM Corp. 1998 15