Terminating the bus, Scsi differential - lvd, Sas interface – Dell TL2000 User Manual
Page 48: Fibre channel interface, Interface, Fibre, Channel, Terminating, Scsi, Differential
The
Medium
Changer
device
is
required
to
be
addressed
via
LUN
1
of
the
lowest-numbered
drive
position
of
each
logical
library.
The
Medium
Changer
device
may
additionally
be
addressed
via
LUN
1
of
other
drives
in
any
logical
library.
Any
bus
containing
a
Medium
Changer
device
via
LUN
1
of
a
drive
is
referred
to
as
a
control
and
data
path.
Any
other
bus
is
referred
to
as
a
data
path.
For
information
about
control
paths,
see
Terminating
the
Bus
The
SCSI
bus
and
all
of
the
wires
in
the
SCSI
cable
must
be
properly
terminated
according
to
the
SCSI
standard.
You
can
plug
an
external
terminator
into
one
of
the
SCSI
connectors.
A
terminator
must
be
installed
on
the
last
device
on
each
end
of
a
string
of
multiple
devices.
A
terminator
is
included
with
each
SCSI
Ultrium
Tape
Drive.
SCSI
Differential
-
LVD
LVD
tape
devices
support
a
bus
length
of
25
meters
(82
ft.)
point-to-point,
and
12
meters
(39
ft.)
using
multi-drop
interconnection
(daisy-chaining).
For
each
daisy-chained
device,
the
maximum
cable
length
must
be
reduced
by
0.5
meters
(1.6
ft.).
Important:
A
faster
bus
does
not
imply
that
an
attached
device
will
support
that
data
rate,
but
that
multiple
devices
can
operate
on
the
bus
at
that
maximum
speed.
For
a
detailed
table
of
SCSI
terms
and
related
specifications,
refer
to
the
SCSI
Trade
Association
Web
site
at
To
ensure
best
performance,
if
possible,
avoid
daisy-chaining.
SAS
Interface
A
drive
sled
with
a
SAS
(Serial
Attached
SCSI)
interface
can
be
linked
directly
to
controllers.
SAS
is
a
performance
improvement
over
traditional
SCSI
because
SAS
enables
multiple
devices
(up
to
128)
of
different
sizes
and
types
to
be
connected
simultaneously
with
thinner
and
longer
cables;
its
full-duplex
signal
transmission
supports
3.0
Gb/s.
In
addition,
SAS
drives
can
be
hot-plugged.
SAS
drives
will
auto-negotiate
speed.
There
are
no
configurable
topologies
thus
no
feature
switches
associated
with
SAS.
The
SAS
Ultrium
3
and
Ultrium
4
Half
height
drive
sleds
are
single
ported
and
can
only
be
attached
to
one
host.
While
the
Ultrium
4
Full
height
drive
is
dual
ported
and
can
be
attached
to
a
maximum
of
two
hosts,
the
intention
of
the
second
port
is
for
redundancy
for
failover
rather
than
sharing.
Sharing
between
these
two
hosts
is
limited
to
active/passive
cluster
failover.
LAN-free
drive
sharing
is
not
supported.
Ultrium
3
and
Ultrium
4
SAS
drive
sleds
use
the
SFF-8088
connection
at
the
drive
sled
end
and
SFF-8088
or
SFF-8470
at
the
host
adapter
end.
Initially,
only
point-to-point
connections
are
supported.
Fibre
Channel
Interface
Fibre
Channel
allows
for
an
active
intelligent
interconnection
scheme,
called
a
Fabric,
to
connect
devices.
Everything
between
the
ports
on
Fibre
Channel
is
called
the
Fabric.
The
Fabric
is
most
often
a
switch
or
series
of
switches
that
takes
the
responsibility
for
routing.
The
library
allows
the
selection
of
the
following
Fibre
channel
port
behaviors:
3-8
Dell
PowerVault
TL2000
Tape
Library
and
TL4000
Tape
Library
User's
Guide