30.2.2. Objective 2: Discuss the design issues of a hard disk

So, we will see what are the design issues that we have for an hard disk.

This chunk introduces the importance of hard disks as secondary storage devices. Hard disks serve as vital components within a computer system, allowing for the permanent storage of data that cannot be held in volatile memory. This section sets the stage for discussing various design issues associated with hard disks.

Consider hard disks as libraries for a computer. Just like libraries store books for long-term reference and retrieval – which you can’t do with a temporary terminal – hard disks allow computers to save data even after they've been turned off.

So, here we should have two operations basically one is your read, and another one is write. So, in case of read we are going to retrieve the information from disks, I am going to bring it to the processor inside the computer while they are bring it to the computer means we are going to put it into memory.

In this chunk, the focus is on the two fundamental operations performed by hard disks: reading and writing. Reading refers to retrieving data from the disk, while writing involves storing data onto the disk. This shows the hard disk's role in the flow of information to the computer’s processing unit.

Think of it like a person looking for a book in a library. When you want to find information, you 'read' by locating the book (the read operation). When you write a new book, you are 'writing' it down on the library shelf (the write operation).

In case of write operation, whatever data processing we are doing in our computer that is residing in our main memory because it works on Von Neumann stored program principle, and from main memory we are going to store it in our hard disk, so this is the right mechanism.

This chunk elaborates further on the writing mechanism, explaining that before data is written to the hard disk, it resides temporarily in the computer’s main memory (RAM). The Von Neumann architecture emphasizes this separation of storage, thereby highlighting the process of moving non-volatile data to permanent storage.

Imagine you’re drafting a document on your computer. First, you write it out in a text editor (like temporary RAM), and only after you’re satisfied do you save it to your hard disk (the long-term storage).

So, we are using a read write head and through this particular head we are going to either read the information or write the information.

Here we learn about the hardware component known as the read-write head. It is responsible for executing the reading and writing tasks on the hard disk. It functions by moving over the disk’s circular platters, accessing magnetic areas to retrieve or alter data accurately.

Think of the read-write head like a chef flipping through a recipe book. The chef must turn the pages (move the head) to find the right recipe (data) or add notes to a recipe (writing data).

So we are going to make concentric ring and on those particular ring we are going to store our information...

In this part, the text discusses how data is organized on a hard disk. It is stored on concentric rings called tracks, which are divided into smaller segments known as sectors. This structured approach allows for efficient data management and access.

Imagine a circular tart, where each slice represents a sector on the track. Each slice holds a piece of information, and by knowing where to ‘slice’ or look, you can easily retrieve the desired piece.

If I say that block size is your say 512 bytes, then what will happen? In this particular block I can store 512 bytes of information.

This chunk explains the concept of block size, which is a fundamental aspect of data organization in a hard disk. A block is the smallest unit of data that the disk can manage. Knowing the block size is important for understanding how data is read, stored, and retrieved efficiently.

Think of block size like the size of a box where you store items. If your box can only fit 512 bytes worth of files, you’ll need more boxes if you have more data to store, regardless of the total amount. Each box represents a sector.

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