IBM System storage DS6000 Series, Introduction And Planning Manual

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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.
megabyte (MB)
1) For processor storage, real and virtual
storage, and channel volume, 2
20
or 1 048
576 bytes.
2) For disk storage capacity and
communications volume, 1 000 000 bytes.
Metro Mirror
A function of a storage server that
maintains a consistent copy of a logical
volume on the same storage server or on
another storage server. All modifications
that any attached host performs on the
primary logical volume are also performed
on the secondary logical volume. See also
Remote Mirror and Copy and Global
Copy .
MES See miscellaneous equipment
specification .
MIB See management information base .
Micro Channel architecture (MCA)
The rules that define how subsystems and
adapters use the Micro Channel bus in a
computer. The architecture defines the
services that each subsystem can or must
provide.
Microsoft Internet Explorer (MSIE)
Web browser software manufactured by
Microsoft.
migration
The replacement of a system or
subsystem with a different type of system
or subsystem, such as replacing a SCSI
host adapter with a fibre-channel host
adapter. In the context of data migration
regarding the DS6000, the transfer of data
from one storage unit to another, such as
from a 3390 to the DS6000.
MIH See missing-interrupt handler .
mirrored pair
Two units that contain the same data. The
system refers to them as one entity.
mirroring
In host systems, the process of writing the
same data to two disk units within the
same auxiliary storage pool at the same
time.
miscellaneous equipment specification (MES)
IBM field-installed change to a machine.
missing-interrupt handler (MIH)
An MVS and MVS/XA facility that tracks
I/O interrupts. MIH informs the operator
and creates a record whenever an
expected interrupt fails to occur before a
specified elapsed time is exceeded.
MLC See machine level control .
mobile solutions terminal (MoST)
The mobile terminal used by service
personnel.
mode conditioning patch cable
A cable that converts a single-mode signal
from a longwave adapter into a light signal
that is appropriate for multimode fibre.
Another mode conditioning patch cable is
required at the terminating end of the
multimode fibre to convert the signal back
to a single-mode signal for a longwave
adapter.
Model 100
A 2105 Model 100, often simply referred
to as a Mod 100, is an expansion
enclosure for the Enterprise Storage
Server. See also 2105 .
MoST See mobile solutions terminal .
MRPD See machine reported product data .
MSA See multiport serial adapter .
MSIE See Microsoft Internet Explorer .
MTBF See mean time between failures .
Multipath Subsystem Device Driver
See IBM TotalStorage DS6000 Multipath
Subsystem Device Driver .
multiple allegiance
A DS6000 hardware function that is
independent of software support. This
function enables multiple system images
to concurrently access the same logical
volume on the DS6000 as long as the
system images are accessing different
extents. See also extent and parallel
access volumes .
Multiple Device Manager (MDM)
A component of the IBM TotalStorage
Productivity Center that allows
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Introduction and Planning Guide