IBM TOTAL STORAGE DS8000 User Manual
Page 366
redundant
array
of
independent
disks
(RAID)
A
methodology
of
grouping
disk
drives
for
managing
disk
storage
to
insulate
data
from
a
failing
disk
drive.
refresh
FlashCopy
target
volume
An
option
(previously
called
incremental
FlashCopy)
of
the
DS8000
that
creates
a
point-in-time
data
copy
without
copying
an
entire
volume
for
each
point-in-time
copy.
Remote
Mirror
and
Copy
A
feature
of
a
storage
server
that
constantly
updates
a
secondary
copy
of
a
logical
volume
to
match
changes
made
to
a
primary
logical
volume.
The
primary
and
secondary
volumes
can
be
on
the
same
storage
server
or
on
separate
storage
servers.
See
also
Global
Mirror,
Metro
Mirror
and
Global
Copy.
remote
technical
assistance
information
network
(RETAIN)
The
initial
service
tracking
system
for
IBM
service
support,
which
captures
heartbeat
and
call-home
records.
See
also
support
catcher
and
support
catcher
telephone
number.
REQ/ACK
See
request
for
acknowledgment
and
acknowledgment.
request
for
acknowledgment
and
acknowledgment
(REQ/ACK)
A
cycle
of
communication
between
two
data
transport
devices
for
the
purpose
of
verifying
the
connection,
which
starts
with
a
request
for
acknowledgment
from
one
of
the
devices
and
ends
with
an
acknowledgment
from
the
second
device.
The
REQ
and
ACK
signals
help
to
provide
uniform
timing
to
support
synchronous
data
transfer
between
an
initiator
and
a
target.
The
objective
of
a
synchronous
data
transfer
method
is
to
minimize
the
effect
of
device
and
cable
delays.
reserved
allegiance
For
zSeries,
a
relationship
that
is
created
in
a
control
unit
between
a
device
and
a
channel
path,
or
path
group,
when
the
device
completes
a
Sense
Reserve
command.
The
allegiance
causes
the
control
unit
to
guarantee
access
(that
is,
busy
status
is
not
presented)
to
the
device.
Access
is
over
the
set
of
channel
paths
that
are
associated
with
the
allegiance;
access
is
for
one
or
more
channel
programs
until
the
allegiance
ends.
RETAIN
See
remote
technical
assistance
information
network.
S
S/390
IBM
enterprise
servers
based
on
Enterprise
Systems
Architecture/390
(ESA/390).
S/390
is
the
currently
accepted
shortened
form
of
the
original
name
System/390.
S/390
storage
Storage
arrays
and
logical
volumes
that
are
defined
as
connected
to
S/390
servers.
This
term
is
synonymous
with
count-key-data
storage.
SAID
See
system
adapter
identification
number.
SAM
See
sequential
access
method.
SAN
See
storage
area
network.
SBCON
See
Single-Byte
Command
Code
Sets
Connection.
screen
The
physical
surface
of
a
display
device
upon
which
information
is
shown
to
users.
SCSI
See
small
computer
system
interface.
SCSI
device
A
disk
drive
connected
to
a
host
through
an
I/O
interface
using
the
SCSI
protocol.
A
SCSI
device
is
either
an
initiator
or
a
target.
See
also
initiator
and
small
computer
system
interface.
SCSI-FCP
Synonym
for
fibre-channel
protocol,
a
protocol
used
to
transport
data
between
an
open-systems
host
and
a
fibre-channel
adapter
on
an
DS8000.
See
also
fibre-channel
protocol
and
small
computer
system
interface.
SCSI
host
systems
Host
systems
that
are
attached
to
the
DS8000
with
a
SCSI
interface.
Such
host
systems
run
on
UNIX,
i5/OS,
Windows
NT,
Windows
2000,
or
Novell
NetWare
operating
systems.
SCSI
ID
A
unique
identifier
assigned
to
a
SCSI
346
IBM
TotalStorage
DS8000:
Messages
Reference