Maxtor 1925 - Manual (Page 65)

Glossary
G-6 Quickview 40 20/30/40GB AT
M
MB – See megabyte.
MEDIA – The magnetic film that is
deposited or coated on an aluminum
substrate which is very flat and in the
shape of a disk. The media is
overcoated with a lubricant to prevent
damage to the heads or media during
head take off and landing. The media is
where the data is stored inside the disk
in the form of magnetic flux or polarity
changes.
MEGABYTE (MB) – A unit of
measurement equal to 1,024 kilobytes,
or 1,048,576 bytes except when
referring to disk storage capacity.
1 MB = 1,000,000 bytes when
referring to disk storage capacity.
See also kilobyte.
MEGAHERTZ – A measurement of
frequency in millions of cycles per
second.
MHz – See megahertz.
MICROPROCESSOR – The integrated
circuit chip that performs the bulk of
data processing and controls the
operation of all of the parts of the
system. A disk drive also contains a
microprocessor to handle all of the
internal functions of the drive and to
support the embedded controller.
MICROSECOND (µs) – One millionth of
a second (.000001 sec.).
MILLISECOND (ms) – One thousandth
of a second (.001 sec.).
MTTF – MTTF is a basic measure of
reliability for non-repairable systems. It
is the mean time expected until the first
failure of a piece of equipment. MTTF
is a statistical value and is meant to be
the mean over a long period of time and
large number of units. For constant
failure rate systems, MTTF is the
inverse of the failure rate. If failure rate
is in failures/million hours, MTTF =
1,000,000 / Failure Rate for
components with exponential
distributions.
MTTR – Mean Time To Repair. The
average time it takes to repair a drive
that has failed for some reason. This
only takes into consideration the
changing of the major sub-assemblies
such as circuit board or sealed housing.
Component level repair is not included
in this number as this type of repair is
not performed in the field.
O
OVERHEAD – The processing time of a
command by the controller, host
adapter or drive prior to any actual disk
accesses taking place.
OVERWRITE – To write data on top of
existing data, erasing it.
OXIDE – A metal-oxygen compound.
Most magnetic coatings are
combinations of iron or other metal
oxides, and the term has become a
general one for the magnetic coating
on tape or disk.
P
PARTITION – A portion of a hard disk
devoted to a particular operating
system and accessed as one logical
volume by the system.
PERFORMANCE – A measure of the
speed of the drive during normal
operation. Factors affecting
performance are seek times, transfer
rate and command overhead.
PERIPHERAL – A device added to a
system as an enhancement to the basic
CPU, such as a disk drive, tape drive or
printer.
PHYSICAL FORMAT – The actual
physical layout of cylinders, tracks,
and sectors on a disk drive.
PLATED MEDIA – Disks that are