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Glossary – Dell PowerEdge RAID Controller 6i User Manual

Page 135

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Glossary

135

Glossary

A

Adapter

An adapter enables the computer system to access peripheral devices by
converting the protocol of one bus or interface to another. An adapter may also
provide specialized function. For example, a RAID controller is a type of adapter
that provides RAID functions. Adapters may reside on the system board or be an
add-in card. Other examples of adapters include network and SCSI adapters.

Adaptive Read Ahead

Adaptive read ahead is a read policy that specifies that the controller begins
using Read-Ahead caching if the two most recent disk accesses occurred in
sequential sectors. If all read requests are random, the algorithm reverts to Non
read ahead; however, all requests are still evaluated for possible sequential
operation.

Array

A grouping of physical disks that combines the storage space on the physical
disks into a single segment of contiguous storage space. The RAID controller
can group physical disks on one or more channels into an array. A hot spare drive
does not participate in an array.

B

Background Initialization

Background initialization is the automatic check for media errors on physical
disks. It ensures that striped data segments are the same on all physical disks in
a virtual disk. The difference between a background initialization and a
consistency check is that a background initialization is automatic for new virtual
disks. The operation starts within five minutes after you create the disk.

Baseport

Base register of the memory address range provided by the host.

Dell_PERC6.1_UG.book Page 135 Wednesday, April 15, 2009 4:18 PM