Configuration, Four, Partition – Dell TL2000 User Manual
Page 217: System, Examples, Scsi, Element, Addressing
SCSI
Element
Addressing
Every
logical
library
starts
at
the
first
drive
slot
with
the
current
assigned
element
start
address
(default
value
256).
It
will
be
incremented
from
the
bottom
to
the
top
slots
for
every
drive
slot.
There
is
one
exception
to
this
addressing
scheme
to
accommodate
libraries
currently
in
the
field.
A
4U
library
which
contains
only
full
height
drives
will
continue
to
have
the
addresses
assignments
256
and
257,
thus
causing
no
interruptions
to
their
operation.
Drive
slots
will
still
be
incremented
by
1
for
each
drive
slot
position.
Note:
Exchanging
drives
with
different
form
factors
will
result
in
the
library
needing
to
be
reconfigured.
The
SCSI
specification
does
not
allow
gaps
in
the
SCSI
element
addressing.
Special
handling
is
needed
for
empty
drive
slots
to
fulfill
the
specification.
Also
drives
which
are
temporarily
removed
need
to
have
their
address
preserved
to
not
confuse
the
attached
host
and
host
application.
Generally
only
drives
are
reported
which
are
currently
physically
available
or
temporarily
removed.
Empty
(unused)
slots
which
are
located
at
the
bottom
or
the
top
should
not
be
reported,
with
an
exception
in
case
of
a
“removed”
condition.
A
drive
slot
which
does
not
contain
a
drive
and
has
a
position
between
used
slots
needs
to
be
reported
as
a
SCSI
element.
To
signal
the
host
application
that
this
slot
is
not
usable,
its
ACCESS
bit
will
be
disabled.
a77ug164
Drive 3
256
Element Address
Drive 2
256
Element Address
Drive 1
256
Element Address
Magazine
1
Magazine
2
Magazine
3
Magazine
4
Front side
Drive 4
256
Element Address
Figure
A-4.
Configuration
of
a
Four
Partition
System
SCSI Element
Slot
4
3
2
1
SCSI Element
Slot
4
3
2
1
257
256
257
256
258
4U Unit with only FH drives
(1 logical library)
4U Unit with FH and HH drives
(1 logical library)
a77ug165
Figure
A-5.
Examples
of
SCSI
Element
Addressing
Appendix
A.
SCSI
Element
Types
and
Addresses
A-5