American Megatrends MegaRAID Express 500 - Manual (Page 108)

MegaRAID Express 500 Hardware Guide 94
Glossary, Continued
Format The process of writing zeros to all data fields in a physical drive (hard drive) to
map out unreadable or bad sectors. Because most hard drives are factory
formatted, formatting is usually only done if a hard disk generates many media
errors.
GB Shorthand for 1,000,000,000 (10 to the ninth power) bytes. It is the same as
1,000 MB (megabytes).
Host-based Array A disk array with an Array Management Software in its host computer rather
than in a disk subsystem.
Host Computer Any computer that disks are directly attached to. Mainframes, servers,
workstations, and personal computers can all be considered host computers.
Hot Spare A stand-by drive ready for use if another drive fails. It does not contain any user
data. Up to eight disk drives can be assigned as hot spares for an adapter. A hot
spare can be dedicated to a single redundant array or it can be part of the global
hot-spare pool for all arrays controlled by the adapter.
Hot Swap The substitution of a replacement unit in a disk subsystem for a defective one,
where the substitution can be performed while the subsystem is running
(performing its normal functions). Hot swaps are manual.
I/O Driver A host computer software component (usually part of the operating system) that
controls the operation of peripheral controllers or adapters attached to the host
computer. I/O drivers communicate between applications and I/O devices, and in
some cases participates in data transfer.
Initialization The process of writing zeros to the data fields of a logical drive and generating
the corresponding parity to put the logical drive in a Ready state. Initializing
erases previous data and generates parity so that the logical drive will pass a
consistency check. Arrays can work without initializing, but they can fail a
consistency check because the parity fields have not been generated.
Cont’d