31.2.1. Fixed vs Movable Head

Now in that particular case now say I am having concentrated track now I have to read information from those particular track. So, in case of fixed head what will happen I am having separate head for each and every track this is talk about the fixed head. So, for each and every track we are going to keep one head and that head is responsible of read information or write information from that particular track. But in case of movable head what will happen that we are having one particular head ok, that head will move outward and inward.

In this section, we discuss the difference between fixed head and movable head disk systems. A fixed head system has a dedicated read/write head for each track on the disk. This means that data can be accessed quickly since the head is always positioned over the track from which it needs to read or write data. In contrast, a movable head system uses a single read/write head that moves in and out to access different tracks on the disk. This movement can introduce some delay compared to a fixed head system, but it allows for a more compact design.

Imagine your local library. In a fixed head scenario, each book (track) has its own librarian (head) dedicated to it, making it easy and fast to get the book you want. In a movable head system, there's one librarian who has to run around the library to find the right book, which may take a little longer each time someone asks for a different book.

Removable or not this is basically a disk property. So, in case of your removable disk what will happen? We are having a disk drive. We can put one disk, you can do work with that particular disk or we can remove it place another one. But in case of your fixed your disk things, if it is not removable then what will happen? It is will be a permanently mounted.

The difference between removable and fixed disks is centered around their physical properties. Removable disks can be inserted into and out of a disk drive, allowing users to swap them out easily for different data storage needs. Examples include USB drives and CDs. Fixed disks, such as the hard drives found in most computers today, are permanently mounted and cannot be easily removed. This design generally leads to greater reliability and speed for the storage system, as the disk does not require handling and reinstallation.

Think of a removable disk like a library book you can borrow and return – you take it out whenever you need it, but you have to return it to the library when you're done. A fixed disk is akin to the books that are part of the library's collection and cannot be checked out; they stay in the library at all times.

So, what will happen? We can have a pile of platters. I am going to have one drive; so that means, you are having multiple platters and we are going to store our information in multiple surfaces.

In disk technology, multiple platters refer to a stack of disk platters within a single hard disk drive that allows for increased storage capacity. Each platter has two surfaces that can store data. When stacked together, multiple platters enhance the overall capacity of the disk without increasing the physical dimensions significantly. This configuration is efficient and increases the storage density, allowing for more data to be saved in the same physical space.

Consider a multi-layered cake. Each layer (or platter) adds to the overall height (or capacity) of the cake. Just like a cake has more room for frosting and decorations as you add layers, a hard disk with multiple platters can store more data without expanding in size.

But here the control circuitry will be a complex one. Now we can store more information, but to store information and retrieve information the circuitry that we are going to design will be a more complex one, but for this particular organization we are going to get a simple circuit.

Increasing the number of platters or adjusting the bit density complicates the design of the disk's control circuitry. Higher bit density means more data is packed into the same area, which necessitates more sophisticated technology to manage the data storage and retrieval processes effectively. While more information can be stored, it creates challenges in ensuring that the system can still access and manage that information efficiently.

Imagine a library that adds more and more bookshelves to fit within the same room. While this allows them to store more books, it can make it harder to navigate the aisles and locate specific titles. Similarly, as drives store more data in a confined space, the underlying system managing that data must become more advanced to ensure efficient access.

--