IBM 86655RY - Netfinity 7600 - 8665 Hardware Maintenance Manual page 222

low-level format
mapping
MB
menu-driven
mirroring
non-volatile random access memory (NVRAM)
NVRAM Non-volatile random access memory.
OFL
OKY
ONL
overlap To perform an operation at the same time another operation is being
parity The state of being odd or even used as the basis of a method of detecting
parity bit
PFA
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Hardware Maintenance Manual: Netfinity 7600 – Type 8665 Models 1RY, 2RY
The array specifies which drives to include in the striping of data. Each array
is subdivided into one or more logical drives. The logical drives specify the
following:
• The number and size of the physical drives as seen by the operating
system. The operating system sees each defined logical drive as a
physical drive.
• The RAID level. When a logical drive is defined, its ServeRAID level (0, 1,
or 5) is also defined.
The writing of track and sector control information on the disk so that a
computer system can store data in and subsequently retrieve data from the
disk.
The establishing of correspondences between a given logical structure and a
given physical structure.
Megabyte; equal to approximately 1 000 000 bytes.
Concerning application software allowing user to select operations from one
or more menus without entering keyboard commands.
The process of writing the same data to two disk units within the same
auxiliary storage pool (disk array) at the same time. The two disk units
become a mirrored pair, allowing the system to continue when one of the
mirrored units fails.
Random access memory that retains its contents after electrical power is shut
off.
Offline, a good drive that replaces a defunct drive in a RAID level-1 or level-5
array. This drive is associated with the array but does not contain any data.
Drive status remains OFL during the rebuild phase.
Good functional state. The ServeRAID adapter's logical drive state in which
all drives in the array are online and fully operational.
Online, a drive that ServeRAID adapter detects as installed, operational, and
configured into an array appear as this state.
performed; for example, to perform input/output operations while
instructions are being executed by the processing unit.
errors in binary-coded data.
A binary digit appended to a group of binary digits to make the sum of all the
digits, including the appended binary digit, either odd or even as pre-
established.
The firmware of a hard drive uses algorithms to track the error rates on the
drive. The drive alerts the user with a Predictive Failure Analysis (PFA) alert
via the and Netfinity Director when degradation of drive performance
(read/write errors) is detected. When a PFA alert occurs, physical
replacement of the drive is recommended.