Disk Defragmentation - Part 1 (What is?)

 

In this article, we are going to see what defragmentation in our Computer is.

I will cover it up in 2 parts.

Part 1: What is defragmentation? And why should we do it?

Part 2: How to defragment a disk?

Part 1:

Today we use systems with huge disk space. But do we care or know how our data is getting written up inside our computers? Before we decode the term, defragmentation let us understand this first.

We install a variety of programs (either native or 3rd party), store a variety of documents, videos, images, etc., in our systems. With those programs or files, we do multiple CRUD operations. CRUD – Create (Creating a file or installing a program), Read (Reading a file content, viewing a video, hearing a song stored in our system), Update (Update the file stored, editing a video, repairing the installed program to add some features), and Delete (Delete the files stored, uninstalling a program, etc.,). With each of these operations, there is a significant amount of changes that our Hard disk undergoes.

Let us see with an example, how installing a program, storing video and audio file in a fresh PC looks like.

In the above figure, a Software or a Video or an Audio is broken down into small chunks and written into a hard disk. This relatively looks clean for a fresh hard disk.

Let us uninstall the Software, store an image file and delete the Audio file and see how our hard disk looks like.

Now we can see a free space created. This is where our problem starts. When we then delete the existing image and upload a few documents like PDF, Excel, Image and install a Video Editing software in my hard disk

Here as you can see the writing part to hard disk is not consistent. One single PDF file is being broken down into two chunks of a data object and is written in two different blocks within our free space (1 & 3). In between, we can see 2 blocks of free space left blank. (2 & 4). The same is the case with Excel where the writing part is done at blocks 2 & 4. Even the image is broken down and written in 1 & 4 in another row.

In this stage, you can say your hard disk is fragmented. How? – The freed-up space is not organized to hold data about a single object together. In our above case, the same PDF file is broken down into 2 chunks and stored in blocks 1 & 3. We do not have control over how this data is written to the computer. So, when we tried to read this PDF document, it must reorganize itself i.e. collect all PDF-related chunks and organize it to be delivered as a single content. To do this it will take some time, and this is where your system performance goes down.

Now assuming you have understood the fragmentation part, let us jump into defragmentation. By this time, you would have guessed what it is. It is nothing but the reversal of fragmentation. When we defragment the disk, it will reorganize all the related chunks and store them back in the hard disk blocks. Thus, when we try to retrieve an image or excel or try to launch a program installed in our system, it will not take time to reorganize and deliver the content instantly. This is how your hard disk looks like after defragmentation.

It is very important to note that we need to defragment only the mechanical hard drives and not SSD. When we defragment SSD, it will reverse your performance i.e. the performance of the system goes down significantly. How? Defragging a flash drive can decrease the life span of the drive since each time information is written to the drive the flash memory is degraded.

Let us see it in action in our next part.

Watch it in Video: (English)

Watch it in Video: (Tamil)