NEC Storage M100 Series User Manual page 447

User Guide
BBU
See Battery Backup
C
Cache
Cache is a high speed memory component implemented at the controller level that temporarily
holds data so that any subsequent access to that data is faster. If requested data is contained in the
cache, this request can be served by simply reading the cache, which is faster. Otherwise, the data
has to be recomputed or fetched from its original storage location, which is comparatively slower.
Cache Fast Write
Cache Fast Write is a feature that allows data to be held only in cache instead of being written to
disk unless necessary. This improves the data I/O performance.
Challenge Handshake Authentication Protocol
Challenge Handshake Authentication Protocol (CHAP) is a three-way authentication protocol
defined in RFC 1994. During initiator CHAP authentication, the initiator is authenticated from an
iSCSI target (disk array side). In mutual CHAP authentication, the iSCSI target (disk array side) and
the initiator (application server side) perform the authentication mutually.
CHAP
See Challenge Handshake Authentication
CHAP secret
CHAP secret is a password which is used during CHAP authentication.
Cross cable
This cable is used to directly connect two identical devices to each other without the use of a hub or
a switch.
D
Data replication
See Replication.
DE
See Disk Enclosure.
Disk array
A device that treats multiple disks as one large capacity disk. RAID technology is employed for
improving reliability and processing capability.
Disk Array Controller
The Disk Array Controller contains control system components and control disk enclosure(s) where
multiple physical disks are installed.
Disk Enclosure
A unit that contains multiple physical disks.
Release 6.0
Unit.
Protocol.
447
Glossary