Instruction Manual

160 Glossary
Default Encryption State
The encryption state to which an encryption enabled component reverts at
power-on (or after an internal reset such as a firmware upgrade). Encryption
states are of two types: encrypted and not encrypted.
Default Security State
The security state to which a security enabled component is reverted at
power-on (or after an internal reset such as a firmware upgrade).
Security states are of two types: secured and not secured.
D
DDR SDRAM
Double Data Rate Synchronous Dynamic Random Access Memory. This is a
type of SDRAM that provides data throughput at double the rate of
conventional SDRAM. It uses a bursting technique to predict the address of the
next memory location to be accessed and allows two data transfers on each clock
cycle.
Disk
A non-volatile, randomly addressable, rewriteable mass storage device, including
both rotating magnetic and optical storage devices and solid-state storage
devices, or non-volatile electronic storage elements.
Disk Array
A collection of disks from one or more disk subsystems combined using a
configuration utility. The utility
controls the disks and presents them to the
array operating environment as one or more logical drives.
Disk Group
A logical grouping of disks attached to a RAID controller on which one or more
virtual disks can be created.
Disk Migration
Moving a virtual disk or a hot spare from one controller to another by detaching
the physical disks and re-attaching them to the new controller.
PERC7.2_UG.book Page 160 Thursday, March 3, 2011 2:14 PM