Maxtor Computer Drive - Manual (Page 63)

GLOSSARY
Maxtor DiamondMax 8S 40GB SATA G-5
subsequent blocks in advance to anticipate the
next request for data. The look ahead
technique speeds up disk access of sequential
blocks of data.
LOW-LEVEL FORMATTING –
Formatting that creates the sectors on the
platter surfaces so the operating system can
access the required areas for generating the file
structure. Maxtor drives are shipped with the
low-level formatting already done.
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.