Exam 6: External Memory

In a _________ disk there is one read-write head per track and all of the heads are mounted on a rigid arm that extends across all tracks.

Greater ability to withstand shock and damage,improvement in the uniformity of the magnet film surface to increase disk reliability,and a significant reduction in overall surface defects to help reduce read-write errors,are all benefits of ___________.

RAID is a set of physical disk drives viewed by the operating system as a single logical drive.

The typical recording technique used in serial tapes is referred to as _________ recording.

The areas between pits are called _________.

When the magnetizable coating is applied to both sides of the platter the disk is then referred to as _________.

In a __________ disk there is only one read-write head mounted on an arm that can be extended or retracted to be able to be positioned above any track.

A __________ is a circular platter constructed of nonmagnetic material,called the substrate,coated with a magnetizable material.

Flash memory becomes unusable after a certain number of writes.

During a read or write operation,the head rotates while the platter beneath it stays stationary.

The head must generate or sense an electromagnetic field of sufficient magnitude to write and read properly.

To increase density in a straightforward CAV system,modern hard disk systems use a technique known as __________,in which the surface is divided into a number of concentric zones.

The time required to move the disk arm to the required track is the __________.

__________ heads are used in sealed drive assemblies that are almost free of contaminants and the head is actually an aerodynamic foil that rests lightly on the platter's surface when the disk is motionless.

The transfer time to or from the disk does not depend on the rotation speed of the disk.

The _________ strategy employs multiple disk drives and distributes data in such a way as to enable simultaneous access to data from multiple drives,thereby improving I / O performance and allowing easier incremental increases in capacity.

RAID level 0 is not a true member of the RAID family because it does not include redundancy to improve performance.

The SSDs now on the market use a type of semiconductor memory referred to as flash memory.

Data are transferred to and from the disk in __________.

On a movable-head system,the time it takes to position the head at the track is known as __________.