LSI MegaRAID SCSI 320-2 RAID Controller Series 518 Hardware Manual page 147

Mbyte
Multi-threaded
Operating
Environment
Parity
Partition
Physical Disk
Physical Disk
Roaming
Protocol
(Megabyte) An abbreviation for 1,000,000 (10 to the sixth power) bytes.
One Mbyte equals 1,000 Kbytes (kilobytes).
Having multiple concurrent or pseudo-concurrent execution sequences.
Used to describe processes in computer systems. Multi-threaded
processes allow throughput-intensive applications to efficiently use a disk
array to increase I/O performance.
The operating environment includes the host computer where the array
is attached, any I/O buses and adapters, the host operating system, and
any additional software required to operate the array. For host-based
arrays, the operating environment includes I/O driver software for the
member disks, but does not include array management software, which
is regarded as part of the array itself.
Parity is an extra bit added to a byte or word to reveal errors in storage
(in RAM or disk) or transmission. Parity is used to generate a set of
redundancy data from two or more parent data sets. The redundancy
data can be used to reconstruct one of the parent data sets, although it
does not fully duplicate the parent data sets. In RAID, this method is
applied to entire drives or stripes across all disk drives in an array. Parity
data is distributed among all the drives in the system. If a single disk
drive fails, the drive can be rebuilt from the parity of the respective data
on the remaining drives.
An array virtual disk made up of logical disks rather than physical ones.
Also known as logical volume.
A hard disk drive that stores data. A hard disk drive consists of one or
more rigid magnetic discs rotating about a central axle with associated
read/write heads and electronics.
The ability of some adapters to detect when disk drives have been
moved to a different slot in the computer—for example, after a hot swap.
A set of formal rules describing how to transmit data, especially across
a network. Low level protocols define the electrical and physical
standards to be observed, bit- and byte- ordering, and the transmission
and error detection and correction of the bit stream. High level protocols
deal with the data formatting, including the message syntax, the terminal-
to-computer dialogue, character sets, and sequencing of messages.
Copyright © 2002 by LSI Logic Corporation. All rights reserved.
C-5