IBM TOTAL STORAGE DS8000 User Manual
Page 361
longwave
laser
adapter
A
connector
that
is
used
between
a
host
and
the
DS8000
to
support
longwave
fibre-channel
communication.
loop
The
physical
connection
between
a
pair
of
device
adapters
in
the
DS8000.
See
also
device
adapter.
LPAR
See
logical
partition.
LRC
See
longitudinal
redundancy
check.
LRU
See
least
recently
used.
LSS
See
logical
subsystem.
LUN
See
logical
unit
number.
LVM
See
logical
volume
manager.
M
machine
level
control
(MLC)
A
database
that
contains
the
EC
level
and
configuration
of
products
in
the
field.
machine
reported
product
data
(MRPD)
Product
data
gathered
by
a
machine
and
sent
to
a
destination
such
as
an
IBM
support
server
or
RETAIN.
These
records
might
include
such
information
as
feature
code
information
and
product
logical
configuration
information.
mainframe
A
computer,
usually
in
a
computer
center,
with
extensive
capabilities
and
resources
to
which
other
computers
may
be
connected
so
that
they
can
share
facilities.
(T)
maintenance
analysis
procedure
(MAP)
A
hardware
maintenance
document
that
gives
an
IBM
service
representative
a
step-by-step
procedure
for
tracing
a
symptom
to
the
cause
of
a
failure.
management
console
See
IBM
TotalStorage
Management
Console.
Management
Information
Base
(MIB)
1)
A
collection
of
objects
that
can
be
accessed
by
means
of
a
network
management
protocol.
(GC)
2)
The
MIB
record
conforms
to
the
Open
Systems
Interconnection
(OSI)
standard
defined
by
the
International
Organization
for
Standardization
(ISO)
for
the
exchange
of
information.
See
also
simple
network
management
protocol.
MAP
See
maintenance
analysis
procedure.
master
storage
unit
The
physical
unit
that
controls
the
creation
of
consistency
groups
in
a
Global
Mirror
session.
The
master
storage
unit
sends
commands
to
subordinate
storage
units.
A
storage
unit
can
be
a
master
for
only
one
Global
Mirror
session.
Contrast
with
subordinate
storage
unit.
maximum
consistency
group
drain
time
The
value
in
seconds
that
indicates
the
maximum
time
that
writes
from
the
local
site
are
delayed
to
the
remote
site
while
the
current
consistency
group
is
being
formed
at
the
remote
site.
When
this
time
is
exceeded,
the
current
attempt
to
form
a
consistency
group
is
ended
and
another
attempt
is
started.
If
this
time
is
exceeded
five
times,
this
maximum
time
is
ignored
on
the
next
attempt
to
form
a
consistency
group.
The
default
value
is
the
larger
of
four
minutes
or
two
times
the
consistency
group
interval
time
if
this
value
is
set
to
zero.
maximum
coordination
time
The
value
in
milliseconds
that
indicates
the
maximum
time
that
is
allowed
for
host
I/O
to
be
delayed
during
the
coordination
of
the
primary
volumes
of
an
Global
Mirror
session.
The
default
is
50
milliseconds
if
this
value
is
set
to
zero.
MB
See
megabyte.
MC
See
IBM
TotalStorage
Management
Console.
MCA
See
Micro
Channel
architecture.
MDM
See
Multiple
Device
Manager.
mean
time
between
failures
(MTBF)
1)
A
projection
of
the
time
that
an
individual
unit
remains
functional.
The
time
is
based
on
averaging
the
performance,
or
projected
performance,
of
a
population
of
statistically
independent
units.
The
units
operate
under
a
set
of
conditions
or
assumptions.
2)
For
a
stated
period
in
the
life
of
a
functional
unit,
the
mean
value
of
the
lengths
of
time
between
consecutive
failures
under
stated
conditions.
(I)
(A)
medium
For
a
storage
unit,
the
disk
surface
on
which
data
is
stored.
Glossary
341