
Glossary
Compaq Smart Array 5300 Controller User Guide
Glossary-3
COMPAQ CONFIDENTIAL
Writer: John Turner File Name: w-glossary.doc
Codename: SilverHammer Part Number: 135606-004 Last Saved On: 5/23/02 9:56 AM
data guarding
See
RAID
.
data striping
Writing data to logical drives in interleaved chunks (by byte or by sector). This technique
improves system performance.
drive mirroring
See
RAID
.
ECC (error correction and checking) memory
A type of memory that checks and corrects single-bit or multi-bit memory errors (depending
on configuration) without causing the server to halt or corrupt data.
fault tolerance
The ability of a server to recover from hardware problems without interrupting server
performance or corrupting data. Hardware RAID is most commonly used, but there are other
types of fault tolerance—for example, controller duplexing and software-based RAID.
flashing
Updating the flash memory on a system. Flash memory is non-volatile memory that is used to
hold control code such as BIOS information. It is also very fast because it can be rewritten
block by block, rather than byte by byte.
hot spare
See
online spare.
logical drive (
or
logical volume)
A group of physical drives, or part of a group, that behaves as one storage unit. Each
constituent physical drive contributes the same storage volume to the total volume of the
logical drive. Has performance advantages over individual physical drives.
logical drive capacity extension
See
capacity extension.
LVD (low voltage differential)
A type of SCSI signaling that allows a maximum transfer rate of either 80 MB/s or 160 MB/s,
conforming to either the Wide Ultra2 or Wide Ultra3 SCSI standards respectively.