Dell PowerEdge RAID Controller 6i User Manual

Page 140

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Glossary

Fault Tolerance

Fault tolerance is the capability of the disk subsystem to undergo a single drive
failure per disk group without compromising data integrity and processing
capability. The PERC 6 controllers provide this support through redundant
virtual disks in RAID levels 1, 5, 6, 10, 50, and 60.

Fault tolerance is often associated with system availability because it allows the
system to be available during drive failures. In case a disk fails, the PERC 6
controllers support hot spare disks and the auto-rebuild feature.

Firmware

Software stored in read-only memory (ROM) or Programmable ROM (PROM).
Firmware is often responsible for the behavior of a system when it is first turned
on. A typical example would be a monitor program in a system that loads the
full operating system from disk or from a network and then passes control to the
operating system.

Foreign Configuration

A RAID configuration that already exists on a replacement physical disk that
you install in a system. You can import the existing configuration to the RAID
controller or clear it so you can create a new one.

Format

The process of writing a specific value to all data fields on a physical disk, to
map out unreadable or bad sectors. Because most physical disks are formatted
when manufactured, formatting is usually done only if a physical disk generates
many media errors.

G

GB

Acronym for gigabyte(s). A gigabyte equals 1,024 megabytes or 1,073,741,824
bytes (2^30 bytes).

Dell_PERC6.1_UG.book Page 140 Wednesday, April 15, 2009 4:18 PM

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