31.1.4. Individual Tracks and Sector Addressing

Secondly disk rotate in a constant angular velocity. Now you just see since it is rotating a constant angular velocity, so the time required to cover this particular length will be equal to time required to traverse this particular length, because it is rotating in a constant angular velocity. So, this angular velocity is constant same. So, this since it is angular velocity is same. So, this cone will be traversed in a constant time so that means, this information will be retrieved in lesser time and that information also retrieved in the same time ok.

This section discusses how disks operate under constant angular velocity, meaning they rotate at the same speed throughout their operation. Because of this consistent speed, the time required to access data on different parts of the disk (whether on the inner or outer tracks) remains constant. This efficiency allows for quicker data retrieval, as the disk doesn’t slow down or speed up based on the track's position. Constant angular velocity simplifies the process of accessing data, ensuring that every data segment can be reached within a uniform timeframe.

Think of a ferris wheel that is consistently turning at the same speed. No matter where a rider is located—whether at the top, on the side, or at the bottom—they experience the same rotation time to complete one cycle. Similarly, a disk’s consistent speed ensures that regardless of where data is located (inner track or outer track), it can be accessed in the same amount of time.

So, time required to retrieve the information from a particular sector is same whether it is an inner track or a outer track ok, so it works on constant angular velocity. So, give pie shaped sector, and concentric track, you can see it; individual track and sector addressable.

This part focuses on the structure of disks, explaining that they consist of individual tracks and sectors. Each track can be visualized as a circular band on the disk, while sectors are segments of those tracks. The key takeaway is that because of their design, each sector can be addressed individually, allowing for precise data retrieval regardless of where it is located on the disk.

Imagine a pizza with several slices. Each slice represents a sector, and each layer of the pizza could represent a track. No matter which slice you choose, you can easily point to it and take it without affecting the others. This is similar to how data is stored and accessed on a disk.

But here we are traversing more amount of time, so it is traversed in a constant angular velocity. So, give pie shaped sector, and concentric track, you can see it; individual track and sector addressable. Now we see why we say that individual tracks and address of sector rule. Move head to give track and wait for a given sector then waste of space in outer track because already I have mentioned that it is having a lesser bit density.

This section discusses the challenges associated with disk storage, particularly regarding wasted space on outer tracks. Since outer tracks have a larger circumference, they can accommodate more data. However, due to lower bit density, the effective use of space isn't optimal. As the read/write head moves over tracks, if the outer track has less information packed in, it leads to inefficiency and wasted space.

Imagine you have a long piece of string (the outer track) and you want to fit beads (data) onto it. At first, you can fit a lot of beads because the string is so wide, but as you get towards the end of the string, you have to leave gaps between the beads, leading to wasted space. This waste represents how outer tracks can end up storing less useful data.