Administrator Guide

local device
A combination of one or more extents to which you add specific RAID properties. Local devices use storage from only one
cluster.
logical unit number (LUN)
Virtual storage to which a given server with a physical connection to the underlying storage device may be granted or denied
access. LUNs are used to identify SCSI devices, such as external hard drives that are connected to a computer. Each device is
assigned a LUN number which serves as the device's unique address.
M
Management Module Control Station (MMCS)
The management entity (management server) is VS6 hardware. The first engine in a cluster has two MMCS: A and B. All the
remaining engines have Akula management modules for the management connectivity.
megabit (Mb)
1,048,576 (2^20) bits. Often rounded to 10^6.
megabyte (MB)
1,048,576 (2^20) bytes. Often rounded to 10^6.
metavolume
A storage volume used by the system that contains the metadata for all the virtual volumes managed by the system. There is
one metadata storage volume per cluster.
Metro-Plex
Two metro node Metro clusters connected within Metro (synchronous) distances, approximately 60 miles or 100 kilometers.
MetroPoint consistency group (Metro group)
A consistency group that is protecting a DR1 volume in a MetroPoint topology.
mirroring
The writing of data to two or more disks simultaneously. If one of the disk drives fails, the system can instantly switch to one of
the other disks without losing data or service. RAID 1 provides mirroring.
mirroring services
Mirroring features provided through a storage service profile.
miss
An operation where the cache is searched but does not contain the data, so the data instead must be accessed from disk.
N
namespace
A set of names recognized by a file system in which all names are unique.
network
System of computers, terminals, and databases connected by communication lines.
network architecture
Design of a network, including hardware, software, method of connection, and the protocol used.
network-attached storage (NAS)
Storage elements connected directly to a network.
network partition
When one site loses contact or communication with another site.
Glossary
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