Dell DC, 3, User Manual

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Glossary 241
Initialization— The process of writing zeros to the data fields of a logical
drive and generating the corresponding parity to bring the logical drive to 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.
Logical Disk— A set of contiguous chunks on a physical disk. Logical disks
are used in array implementations as constituents of logical volumes or
partitions. Logical disks are normally transparent to the host environment,
except when the array containing them is being configured.
Logical Drive— A virtual drive within an array that can consist of more than
one physical drive. Logical drives divide the contiguous storage space of an
array of hard drives or a spanned group of arrays of drives. The storage space
in a logical drive is spread across all the physical drives in the array or
spanned arrays. Configure at least one logical drive for each array.
Mapping— The conversion between multiple data addressing schemes,
especially conversions between member disk block addresses and block
addresses of the virtual disks presented to the operating environment by
Array Management Software.
Megabyte (MB)— An abbreviation for 1,000,000 (10 to the sixth power)
bytes. It is the same as 1,000 KB (kilobytes).
Multi-threaded— Having multiple concurrent or pseudo-concurrent
execution sequences. Used to describe processes in computer systems.
Multi-threaded processes allow throughput-intensive applications to
efficiently use a disk array to increase I/O performance.
Operating Environment— The operating environment includes the host
computer where the array is attached, any I/O buses and adapters, the host
operating system, and any additional software required to operate the array.
For host-based arrays, the operating environment includes I/O driver
software for the member disks, but does not include Array Management
Software, which is regarded as part of the array itself.