Compaq ProLiant 1600 Administrator's Manual page 175

Quorum disk
RA4000
RAID
Redundant Array
of Inexpensive
Disks
Redundancy
Reliability
Rescan
A device managed by Microsoft Cluster Server
(MSCS) that provides a means for persistent storage
of the cluster configuration information required for
failover and failback events as well as for arbitrating
ownership of cluster resources.
See Compaq StorageWorks RAID Array 4000
See Redundant Array of Inexpensive Disks
A method of using hard disk drives in an array to
provide data redundancy to increase system reliability
and performance. RAID is classified in the following
levels:
Data striping. This RAID level stripes data
RAID 0
across all drives of the array, but does not
incorporate a method to create redundant data.
RAID 0 does not provide fault tolerance.
Drive mirroring. This level creates fault
RAID 1
tolerance by storing two sets of duplicate data
on a pair of disk drives.
Data guarding. This level involves the use of a
RAID 4
single, designated drive containing parity data.
If a drive fails, the controller uses the data on
the parity drive and the remaining drives to
reconstruct data from the failed drive.
Distributed data guarding. This level stores
RAID 5
parity data across all the drives in the array.
Spreading the parity across all the drives
allows more simultaneous read operations and
higher performance than data guarding
(RAID 4).
The provision of multiple, interchangeable
components to perform a single function in order to
cope with failures and errors. A RAID set is
considered to be redundant when user data is recorded
directly to one member and all of the other members
include associated parity information.
The continuous integrity of a system (server, storage,
network, or cluster).
The ability to check for new or lost logical disks or an
array controller on the loop.
Glossary-5