Computer Science - Computer Fundamentals - Discussion

Cylinder is the right answer.

Tracks and Cylinders. The idea of a cylinder is an artifact of the mechanical nature of the actuators used to move the read/write heads on a modern disk. It is faster to read sectors from the same track than it is to move to another track, even one close by. We now consider the fact that standard disk drives with concentric tracks and multiple recording surfaces have the same number of tracks and track geometry on each of the surfaces.

When the actuator is functioning properly, as it almost always is, each read/write head is over (or near to) the same numbered track on its disk. This leads to the idea of a cylinder as the set of tracks that can be read without significant repositioning of the read/write heads. In early disk designs, with wider tracks, there would be no positioning required to move from surface to surface on a cylinder. All that would be required was an electronic switching of the active head, a matter of nanoseconds and not milliseconds.

I think this question and answer is wrong. R/W head should be re-positioned to access the cylinder. What Mr.Sundar said is correct "Track (track number N) from all discs (vertically) forms a cylinder". There is only one r/w head for each disk surface. So to access each cylinder (tracks on each disk) head should move.

This question should be "The part on a disk which can be accessed without re-positioning the R/W heads is" and the answer is SURFACE.

Tracks are concentric circles divided on the surface of plate of hard disk. As there are more than one plate in hard disk. This circles and plates looks like cylinder. Here I can't so diagrammatically but understand me. It is other name for tracks.

About cluster it is term that defines allocation of memory in file system. Fs like ntfs produces clusters during formatting and its size is defined during formatting.

Cylinders are vertically formed by tracks. In other words, track 12 on platter 0 plus track 12 on platter 1 etc. is cylinder 12. The number of cylinders of a disk drive exactly equals the number of tracks on a single surface in the drive.

So, in order to access a particular cylinder from a track we do not need to move R/W head from that particular track.

Track - Circular portion that passes under read and writes head as the disk rotates.

Sectors - Each track is divided into sectors with fixed number of bytes.

Cluster - Fixed number of sectors treated as one unit for storage by the operating system.

Cylinder- recording of data vertically reduces access arm movement.

Cluster & Surface are scatter. The R/W head has to move forward and backward. So from this, All of the Above option is wrong.

Cylinder is the Plate itself. So the R/W head always touch it. :-).

The cylinder can be defined as a division of disk drive data and it is used in the 'Fixed block architecture' of the disk. Here the 'number of cylinders' equals the 'number of tracks'.

The technology is used in a magnetic disk, where the read and write operation function on track and the tracks is the collection of multiple segments where the data are stored.

Track (track number N) from all discs (vertically) forms a cylinder.

Since cylinder is rotating we no need to move the R/W head to access the data.

I know only, the cylinder is nothing but group of disks. So, these group of disks (cylinder) can't help to provide the movement of read/write head.