Understanding Hard Drive Defragmentation

Defragmentation of a PC hard drive, also commonly called defrag, is a process with a sort of guttural, ominous tone. The defrag process has two positive aspects, improved retrieval or response time and ease of reconstruction. Imagination and imagery are probably the easiest ways to understand the defragmentation process. The first example looks at fragments, how they are created and how defragmentation deals with them.

Example : Imagine two large city libraries, each has hundreds of file cabinets immediately behind the librarian at the front desk, some are nearly full, some partially full. A donation is made to each library entitled THE NEW DATA which has 14 chapters in a loose-leaf binder.

The first librarian catalogs and stores chapters 1 - 3 wherever there is room in a drawer, chapter 4 in another drawer, chapter 5 and 6 in yet another, and so on. The librarian has taken THE NEW DATA and separated it into parts or fragments for storage purposes, using whatever space is available.

The librarian at the other library also catalogs and stores the 14 chapters, however, as one item, still together in the binder in one drawer.

If a person comes to the first librarian and asks for THE NEW DATA, the wait for retrieval or response time is certain to take longer than the response time from the second librarian, who retrieves from only one location.

Retrieving files from multiple stored locations and restoring them to the original format is the major factor in degraded response time of hard drives.

A second scenario is to imagine if both library contents have to be reconstructed due to massive damage such as smoke or water. The first library will be extremely difficult to reconstruct or may never be able to reconstruct the damaged files because of the many drawers they were stored in.

The second library might be difficult to reconstruct but has a greater chance of success because the data is logically grouped and missing pieces can be identified and possibly recreated as necessary. The reconstruction of a PC hard drive operates on the same basis.

The defragmentation process is simply grouping data together that was previously split apart and stored randomly on the hard drive. A defragmentation program is available in all Windows operating systems and should be run whenever your computer is lagging or freezing.

Resource: Personal Experience