Hitachi CBL, Hardware Service Manual

Page: 283 / 292

Glossary–9
Hitachi Unified Storage Hardware Service Guide
•
A B C D E F G H I
J K
L M
N O
P
Q
R S T U V W
X Y
Z
that uses an extra checking bit, called the parity bit, to allow the
receiver to verify that the data is error free. Parity data in a RAID array
is data stored on member disks that can be used for regenerating any
user data that becomes inaccessible.
Parity groups
RAID groups can contain single or multiple parity groups where the
parity group acts as a partition of that container.
Point-to-Point
A topology where two points communicate.
Port
An access point in a device where a link attaches.
Primary or local site
The host computer where the primary data of a remote copy pair
(primary and secondary data) resides. The term “primary site” is also
used for host failover operations. In that case, the primary site is the
host computer where the production applications are running, and the
secondary site is where the backup applications run when the
applications on the primary site fail, or where the primary site itself
fails.
R
RAID
Redundant Array of Independent Disks. A storage system in which part
of the physical storage capacity is used to store redundant information
about user data stored on the remainder of the storage capacity. The
redundant information enables regeneration of user data in the event
that one of the storage system's member disks or the access path to it
fails.
RAID group
A set of disks on which you can bind one or more volumes.
Remote path
A route connecting identical ports on the local storage system and the
remote storage system. Two remote paths must be set up for each
storage system (one path for each of the two controllers built in the
storage system).