HP StorageWorks XP24000/XP20000 Disk Array Owner Guide (AE131-96081, September 2010)

failover An operation that reverses replication direction so that the destination becomes
the source and the source becomes the destination. Failovers can be planned or
unplanned and can occur between DR groups, managed sets, fabrics or paths,
and array controllers.
FC Fibre Channel. A network technology primarily used for storage networks.
FC-AL Fibre Channel arbitrated loop.
FCP Fibre Channel protocol.
fence level A method of setting rejection of P9000 or XP Continuous Access write I/O
requests from the host according to the condition of mirroring consistency.
FICON Fibre connectivity. Hardware that connects the mainframe to the control unit.
FSW Fibre switch.
GLM Gigabit link module. A 1 Gb/s fiber optic transceiver.
HA High availability.
HBA Host bus adapter. A built-in function or a card installed in a PC or other host
computer to enable connection of the host to the SAN.
HDD Hard disk drive.
HDU Hard disk unit.
host mode Each port can be configured for a particular host type. These modes are
represented as two-digit hexadecimal numbers. For example, host mode 08
represents an HP-UX host.
hot standby The act of using one or more servers (or disks) as a standby in case of a primary
server (disk) failure.
LD, LDEV Logical device. An LDEV is created when a RAID group is carved into pieces
according to the selected host emulation mode (that is, OPEN-3, OPEN-8,
OPEN-9). The number of resulting LDEVs depends on the selected emulation
mode. The term LDEV is also known as term volume.
local disk A disk in the local array. Sometimes refers to a disk in a local host.
LUN Logical unit number. A LUN results from mapping a SCSI logical unit number,
port ID, and LDEV ID to a RAID group. The size of the LUN is determined by the
emulation mode of the LDEV, and the number of LDEVs associated with the LUN.
For example, a LUN associated with two OPEN-3 LDEVs has a size of 4,693
MB.
LUSE Logical Unit Size Expansion. The LUSE feature is available when the HP
StorageWorks LUN Manager product is installed, and allows a LUN, normally
associated with only a single LDEV, to be associated with 1 to 36 LDEVs.
Essentially, LUSE makes it possible for applications to access a single large pool
of storage.
MCU Main control unit.
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