Glossary
1
10Gb Ethernet
A 10 gigabit per second (Gb/s) Ethernet
connection using either fiber-optic cables or
twisted-pair copper wires.
10Gb iSCSI
An iSCSI connection that runs on a 10Gb
Ethernet network.
10GE
See “10Gb Ethernet” and “10Gb iSCSI”.
2
2-Port Active-Active (2PAA) mode
A system mode for Nexsan storage systems. In
this mode, each RAID controller operates as an
independent node, but only one port is active on
each controller. The second port operates in
passive mode. Port 0 is active on controller 0,
and port 1 is active on controller 1. The volumes
are mapped to the active port on their owning
controller. When one controller fails, the passive
port on the other controller activates and takes
over the host port functions of the failed
controller. In a switched environment, failover is
completely transparent to the hosts.
4
4-Port Active-Active (4PAA) mode
A system mode for Nexsan storage systems. In
this mode, each RAID controller operates as an
independent node, and all ports are active. Port 0
is the primary port on controller 0, and port 1 is
the primary port on controller 1. The volumes
must be mapped to at least one port on its
owning controller and to the secondary port on
the other controller, which requires the host to be
configured for multipathing. When one controller
fails, the secondary port on the other controller
takes on the host address of the primary port on
the failed controller, allowing host I/O to continue
(see failover); the host sees the storage become
active through its second path.
A
active drawer
A slide-out container on the front of Nexsan E-
Series storage units that houses the disk drives
used by the unit for data storage. Also
sometimes referred to as a “pod” in event logs
and other internal statistics.
All Ports All LUNs (APAL) mode
A system mode for Nexsan storage systems. In
this mode, the entire system operates as a single
node. The volumes can be mapped to any or all
ports on both RAID controllers. When a
controller fails, the ports on that controller
become inaccessible. However, if the volumes
are mapped to ports on the other controller as
well (which requires the host to be configured for
multipathing), they remain accessible to the
host, which sees the storage become active
through its second path.
array
A linked group of one or more physical,
independent hard disk drives. See also “RAID”.
AutoMAID
Nexsan’s proprietary system which reduces the
energy consumption of disk drives that are in an
idle state. AutoMAID is organized into four
levels, which can be configured, customized, or
even overridden by the customer according to
performance needs. Each AutoMAID level
reduces disk drive energy consumption further
than the last. AutoMAID is referred to as
“Nexsan AutoMAID energy-saving technology”
in sales, marketing, and media. Nexsan
AutoMAID technology incorporates disk
protection functions not found in other MAID
systems. See also “MAID”.
Glossary
Nexsan High-Density Storage
User Guide
254