Adaptec DuraStor 7220SS User Manual page 126

Glossary
L
logical unit number
See LUN.
loop address
A loop address is an fibre channel (FC) term that indicates the
unique ID of a node in FC loop topology. A loop address is
sometimes referred to as a Loop ID.
LUN
Stands for logical unit number. The number assigned to a
subdevice (logical unit) of a SCSI device. Each SCSI device can
contain up to 63 subdevices numbered 0 through 63; however,
most SCSI devices contain only one subdevice (LUN 0). On storage
systems, each array is assigned and accessed by its own LUN.
M
metadata
Data written on each disk drive that describes the arrays,
partitions, and free space on the disk drive. This data is only
accessible to the controller.
mirror set (RAID 1)
An array type made up of two equal-sized partitions that reside on
two different disk drives. A mirror set stores and maintains the
same (redundant) data in each of the two partitions. See also
partition; redundancy.
multilevel array
An array that contains other arrays. See also array; stripe set of
mirror sets (RAID 0/1); stripe set of RAID 5 sets (RAID 50).
P
parity
A form of error correcting redundancy used to re-create the data of
a failed disk drive in a RAID 3, 4, or 5 set. See also RAID 3; RAID 4;
RAID 5; redundancy.
Glossary-5