IBM Partner Pavilion DS4100 User Manual
Page 169

random-access
memory
(RAM).
A
temporary
storage
location
in
which
the
central
processing
unit
(CPU)
stores
and
executes
its
processes.
Contrast
with
DASD.
RDAC.
See
redundant
disk
array
controller.
read-only
memory
(ROM).
Memory
in
which
stored
data
cannot
be
changed
by
the
user
except
under
special
conditions.
recoverable
virtual
shared
disk
(RVSD).
A
virtual
shared
disk
on
a
server
node
configured
to
provide
continuous
access
to
data
and
file
systems
in
a
cluster.
redundant
array
of
independent
disks
(RAID).
A
collection
of
disk
drives
that
appears
as
a
single
volume
to
the
server
and
are
fault
tolerant
through
mirroring
or
parity
checking.
redundant
disk
array
controller
(RDAC).
(1)
In
hardware,
a
redundant
set
of
controllers
(either
active/passive
or
active/active).
(2)
In
software,
a
layer
that
manages
the
input/output
(I/O)
through
the
active
controller
during
normal
operation
and
transparently
reroutes
I/Os
to
the
other
controller
in
the
redundant
set
if
a
controller
or
I/O
path
fails.
remote
mirroring.
Online,
real-time
replication
of
data
between
storage
subsystems
that
are
maintained
on
separate
media.
The
Enhanced
Remote
Mirror
Option
is
a
DS4000
premium
feature
that
provides
support
for
remote
mirroring.
See
also
Global
Mirroring,
Metro
Mirroring.
ROM.
See
read-only
memory.
router.
A
computer
that
determines
the
path
of
network
traffic
flow.
The
path
selection
is
made
from
several
paths
based
on
information
obtained
from
specific
protocols,
algorithms
that
attempt
to
identify
the
shortest
or
best
path,
and
other
criteria
such
as
metrics
or
protocol-specific
destination
addresses.
RVSD.
See
recoverable
virtual
shared
disk.
SAI.
See
Storage
Array
Identifier.
SA
Identifier.
See
Storage
Array
Identifier.
SAN.
See
storage
area
network.
SATA.
See
serial
ATA.
scope.
Defines
a
group
of
controllers
by
their
Internet
Protocol
(IP)
addresses.
A
scope
must
be
created
and
defined
so
that
dynamic
IP
addresses
can
be
assigned
to
controllers
on
the
network.
SCSI.
See
small
computer
system
interface.
segmented
loop
port
(SL_port).
A
port
that
allows
division
of
a
fibre-channel
private
loop
into
multiple
segments.
Each
segment
can
pass
frames
around
as
an
independent
loop
and
can
connect
through
the
fabric
to
other
segments
of
the
same
loop.
sense
data.
(1)
Data
sent
with
a
negative
response,
indicating
the
reason
for
the
response.
(2)
Data
describing
an
I/O
error.
Sense
data
is
presented
to
a
host
system
in
response
to
a
sense
request
command.
serial
ATA.
The
standard
for
a
high-speed
alternative
to
small
computer
system
interface
(SCSI)
hard
drives.
The
SATA-1
standard
is
equivalent
in
performance
to
a
10
000
RPM
SCSI
drive.
serial
storage
architecture
(SSA).
An
interface
specification
from
IBM
in
which
devices
are
arranged
in
a
ring
topology.
SSA,
which
is
compatible
with
small
computer
system
interface
(SCSI)
devices,
allows
full-duplex
packet
multiplexed
serial
data
transfers
at
rates
of
20
Mbps
in
each
direction.
server.
A
functional
hardware
and
software
unit
that
delivers
shared
resources
to
workstation
client
units
on
a
computer
network.
server/device
events.
Events
that
occur
on
the
server
or
a
designated
device
that
meet
criteria
that
the
user
sets.
SFP.
See
small
form-factor
pluggable.
Simple
Network
Management
Protocol
(SNMP).
In
the
Internet
suite
of
protocols,
a
network
management
protocol
that
is
used
to
monitor
routers
and
attached
networks.
SNMP
is
an
application
layer
protocol.
Information
on
devices
managed
is
defined
and
stored
in
the
application’s
Management
Information
Base
(MIB).
SL_port.
See
segmented
loop
port.
SMagent.
The
DS4000
Storage
Manager
optional
Java-based
host-agent
software,
which
can
be
used
on
Microsoft
Windows,
Novell
NetWare,
HP-UX,
and
Solaris
host
systems
to
manage
storage
subsystems
through
the
host
fibre-channel
connection.
SMclient.
The
DS4000
Storage
Manager
client
software,
which
is
a
Java-based
graphical
user
interface
(GUI)
that
is
used
to
configure,
manage,
and
troubleshoot
storage
servers
and
expansion
units
in
a
DS4000
storage
subsystem.
SMclient
can
be
used
on
a
host
system
or
on
a
storage
management
station.
SMruntime.
A
Java
compiler
for
the
SMclient.
SMutil.
The
DS4000
Storage
Manager
utility
software
that
is
used
on
Microsoft
Windows,
HP-UX,
and
Solaris
host
systems
to
register
and
map
new
logical
drives
to
the
operating
system.
In
Microsoft
Windows,
it
also
contains
a
utility
to
flush
the
cached
data
of
the
operating
system
for
a
particular
drive
before
creating
a
FlashCopy.
Glossary
137