EMC Symmetrix DMX-3

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EMC Symmetrix DMX-3 Product Guide
Glossary
M
MA Multiple Allegiance is an IBM feature, supported by the Symmetrix
system, that improves throughput across a shared storage
environment. MA allows more than one I/O from different hosts to
access the same device as long as the I/Os do not conflict with each
other.
media The disk surface on which data is stored.
megabyte (MB) The MB
2
value is based on the convention:
1 MB = 1024 * 1024 bytes.
The MB
10
value is based on the convention:
1 MB = 1000 * 1000 bytes.
Although these values are expressed differently, their values are
equivalent
.
metadevice A group of components (physical partitions) accessed as a single
logical device through concatenating, striping, mirroring, logging the
physical devices, or setting up RAID devices.
MII Machine Initiated Interrupt.
mirroring The Symmetrix option that maintains two identical copies of a
designated volume on separate disks. Each volume automatically
updates during a write operation. If one disk drive fails, the
Symmetrix system automatically uses the other disk drive.
mirrored pair A logical volume with all data recorded twice, once on each of two
different physical devices.
MPCD Multiprotocol Channel Director
MVS Multiple Virtual Storage (mainframe systems only).
multiprotocol channel
director
The Symmetrix DMX-3 MPCD can be configured with various
mezzanine cards, which support connects to hosts using iSCSI and
FICON protocols. A GigE remote support mezzanine card supports
connections between Symmetrix systems running SRDF.