IBM 2145UPS-1U Hardware Installation Manual page 211

of ISLs traversed is the number of ISL hops on the shortest route between
the pair of nodes that are farthest apart in the fabric.
J
JBOD (just a bunch of disks)
IBM definition: See non-RAID.
HP definition: A group of single-device logical units not configured into
any other container type.
L
LBA See logical block address.
least recently used (LRU)
An algorithm used to identify and make available the cache space that
contains the least-recently used data.
line card
See blade.
local fabric
In SAN Volume Controller, those storage area network (SAN) components
(such as switches and cables) that connect the components (nodes, hosts,
switches) of the local cluster together.
local/remote fabric interconnect
The storage area network (SAN) components that are used to connect the
local and remote fabrics together.
logical block address (LBA)
The block number on a disk.
logical unit (LU)
An entity to which Small Computer System Interface (SCSI) commands are
addressed, such as a virtual disk (VDisk) or managed disk (MDisk).
logical unit number (LUN)
The SCSI identifier of a logical unit within a target. (S)
longitudinal redundancy check (LRC)
A method of error checking during data transfer that involves checking
parity.
See longitudinal redundancy check.
LRC
See least recently used.
LRU
See logical unit.
LU
See logical unit number.
LUN
LUN masking
A process that allows or prevents I/O to the disk drives through the
host-bus-adapter (HBA) device or operating-system device driver.
M
managed disk (MDisk)
A Small Computer System Interface (SCSI) logical unit that a redundant
array of independent disks (RAID) controller provides and a cluster
manages. The MDisk is not visible to host systems on the storage area
network (SAN).
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Glossary