Mini-hubs
The
mini-hubs
are
located
on
the
back
of
the
DS4400
Storage
Server
(see
Figure
52
on
page
64).
A
mini-hub
is
a
single,
removable
unit
that
provides
the
Fibre
Channel
interface
between
a
DS4400
Storage
Server
and
hosts
or
drives.
The
back
of
the
DS4400
Storage
Server
can
accommodate
eight
mini-hubs:
up
to
four
host-side
and
up
to
four
drive-side
mini-hubs.
Each
mini-hub
has
two
ports.
An
SFP
module
is
installed
in
a
mini-hub
port;
then,
a
fiber-optic
interface
cable
is
connected
into
the
SFP
module.
For
more
information,
see
“Fibre
Channel
connections”
on
page
4
and
“Small
Form-Factor
Pluggable
(SFP)
Modules”
on
page
58.
Servicing
notes
Consider
the
following
when
servicing
mini-hubs:
v
You
can
hot
swap
(replace)
a
failed
mini-hub
while
the
DS4400
Storage
Server
is
in
operation.
v
Four
indicator
lights
provide
status
information.
If
a
mini-hub
fails,
the
interface
fault
and
the
bypass
indicator
lights
on
the
mini-hub
are
lit
and
the
loop
good
indicator
light
is
off.
For
more
information
about
indicator
lights,
see
“Mini-hub
indicator
lights”
on
page
33.
v
If
you
replace
the
mini-hub
and
the
SFP
modules
in
them
and
still
experience
problems,
the
DS4400
Storage
Server
might
have
defective
components
or
connections.
Check
the
storage-management
software
for
indications
of
other
component
failures.
For
more
information,
see
“Fibre
Channel
connections”
on
page
43
and
“Interface
ports”
on
page
145.
Replacing
a
failed
mini-hub
When
instructed
by
the
storage-management
software,
replace
a
mini-hub.
Use
the
following
procedure
to
replace
either
a
failed
host-side
or
drive-side
mini-hub.
Attention:
To
prevent
possible
data
loss,
do
not
remove
cables
from
a
mini-hub
that
has
not
failed.
Note:
You
must
remove
the
fiber-optic
cable
from
the
SFP
module
before
you
can
remove
the
SFP
module
from
the
mini-hub
port.
1.
On
the
mini-hub
that
has
failed,
remove
the
fiber-optic
cables
from
the
SFP
modules,
as
shown
in
Figure
51
on
page
64.
For
proper
handling
of
fiber-optic
cables,
see
“Handling
fiber-optic
cables”
on
page
5.
Chapter
3.
Replacing
DS4400
Storage
Server
components
63
Summary of Contents for TotalStorage DS4400
Page 1: ...IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide GC26 7730 00...
Page 2: ......
Page 3: ...IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide GC26 7730 00...
Page 7: ...Glossary 75 75 Index 85 Contents v...
Page 8: ...vi IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 10: ...viii IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 12: ...x IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 18: ...xvi IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 32: ...xxx IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 52: ...20 IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 98: ...66 IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 106: ...74 IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 116: ...84 IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 120: ...88 IBM TotalStorage DS4400 Fibre Channel Storage Server User s Guide...
Page 123: ......
Page 124: ...Printed in USA GC26 7730 00...
