Connecting a redundant drive loop to the ds4500, Connecting, Redundant – IBM TOTALSTORAGE DS4500 User Manual
Page 13: Drive, Loop, Ds4500, Figure

Connecting
a
redundant
drive
loop
to
the
DS4500
Use
the
following
procedure
to
connect
a
redundant
drive
loop
to
the
DS4500
Storage
Subsystem.
You
will
need
two
fiber-optic
cables
for
each
redundant
pair
of
loops
(for
example,
loop
A
and
loop
B)
that
you
are
connecting
to
the
DS4500
Storage
Subsystem.
1.
Connect
drive
loop
A
to
the
DS4500
Storage
Subsystem,
as
shown
in
Starting
with
the
last
storage
expansion
enclosure
in
loop
A,
connect
the
In
port
on
the
left
ESM
board
to
the
Out
(upper)
port
on
drive
mini
hub
4
on
the
DS4500
Storage
Subsystem.
Leave
the
Out
port
on
the
left
ESM
board
on
the
first
storage
expansion
enclosure
and
the
In
(lower)
connector
on
drive
mini
hub
4
unoccupied.
Loop B
Loop D
Loop A
Loop C
Storage expansion
enclosure group 1
Storage expansion
enclosure group 2
Storage server
Figure
13.
Connecting
a
second
redundant
storage
expansion
enclosure
group
(loops
C
and
D)
13