Fibre
channel
loop
and
ID
settings
When
you
install
a
hard
disk
drive
in
the
storage
expansion
enclosure,
the
drive
tray
plugs
into
a
printed
circuit
board
called
the
midplane
.
The
midplane
sets
the
fibre
channel
loop
ID
automatically,
based
on
the
enclosure
ID
switch
setting
and
the
physical
location
(bay)
of
the
hard
disk
drive.
Enclosure
ID
settings
Each
storage
expansion
enclosure
in
a
DS4000
storage
subsystem
drive
loop
must
have
a
unique
drive
enclosure
ID.
DS4000
controllers
use
a
combination
of
the
enclosure
ID
and
the
number
of
the
physical
slot
that
a
fibre
channel
hard
drive
occupies
to
create
a
unique
fibre
channel
loop
address
or
arbitrated
loop
physical
address
(AL_PA)
for
each
drive
in
a
fibre
channel
drive
loop.
The
enclosure
ID
consists
of
two
digits,
a
tens
digit
(x10)
and
ones
digit
(x1).
Attention:
When
connecting
the
storage
expansion
enclosure
to
a
storage
server,
DO
NOT
use
the
tens
digit
(x10)
setting.
Use
only
the
ones
digit
(x1)
setting
to
set
unique
server
IDs
or
enclosure
IDs.
Give
each
storage
expansion
enclosure
in
a
redundant
drive
loop
a
unique
ones
digit
(x1)
ID.
This
setting
will
enforce
hard
AL_PAs
(unchangeable
between
fibre
channel
Loop
Initializations
[LIPs])
for
the
drives
and
facilitate
drive
loop
problem
troubleshooting
in
the
event
of
an
error.
If
the
ones
digits
are
not
unique,
two
or
more
devices
will
have
the
same
hard
AL_PA.
In
such
a
case,
the
controller
will
use
soft
AL_PAs
for
the
devices
that
have
identical
hard
AL_PAs.
The
problem
with
soft
addressing
is
that
addresses
may
change
between
LIPs.
This
possibility
increases
the
difficulty
of
troubleshooting
drive
loop
problems,
since
one
cannot
easily
ascertain
whether
the
same
device
with
a
different
address
or
different
device
may
be
causing
a
problem.
Note:
The
storage
expansion
enclosure
is
shipped
with
00
as
the
default
server
ID
setting.
When
you
connect
the
storage
expansion
enclosure
to
a
storage
server,
you
must
set
the
storage
expansion
enclosure
enclosure
ID
setting
to
a
value
other
than
00.
Each
server
unit
should
have
a
unique
ID
if
it
is
going
1 Gb/s
2 Gb/s
X10
X1
Tray Number
Conflict
Green 2 GB/s LED
Amber Conflict LED
1 Gb/s
2 Gb/s
X10
X1
Tray Number
Conflict
e
xp70010
Figure
20.
Setting
the
interface
options
30
IBM
TotalStorage
DS4000
EXP700
and
EXP710
Storage
Expansion
Enclosures:
Installation,
User’s,
and
Maintenance
Guide
Summary of Contents for TotalStorage DS4000 EXP710
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