(redirected from Disk defragmentation)
Also found in: Dictionary.


(computer science)
A procedure in which portions of files on a computer disk are moved until all parts of each file occupy continuous sectors, resulting in a substantial improvement in disk access times.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


To reorganize the disk by putting files into contiguous order. Because the operating system stores new data in whatever free space is available, data files become spread out across the disk as they are updated. Large files may be broken into thousands of fragments, causing the read/write head to move back and forth numerous extra times to read the data. A "defragger" or "optimizer program" rewrites all the files and stores them in adjacent sectors.

Windows comes with the DEFRAG.EXE utility, which can be activated by the Run dialog from the Start menu. Other popular defraggers, such as Diskeeper, offer enhanced capabilities.

Users Run the Gamut
Some users are fanatical about defragging their disks on a regular basis. Others rarely do it, if ever. After defragmenting, performance increases are most noticeable on very large databases that had been heavily fragmented. Because today's computers are so fast, users may not notice any increase in speed with routine applications such as word processing and spreadsheets, especially if the files are small.

A Good Habit
Nevertheless, defragmenting disks regularly is good practice because it reduces wear and tear on the drive mechanism. In addition, should the hard disk ever crash and you did not back up important files, data recovery experts will tell you that a defragged disk is much easier to restore.

Before and After
This Diskeeper example shows the fragmented files (in red) before defragging and the results below. Diskeeper can be set up to defrag the disk whenever the machine is idle. As soon as the user clicks the mouse or presses a key, the defragging is suspended.
Copyright © 1981-2019 by The Computer Language Company Inc. All Rights reserved. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction is strictly prohibited without permission from the publisher.
References in periodicals archive ?
The disk defragmentation software used was Diskeeper Server.
In our tests with the Kapersky Lab AV solution, the disk defragmentation resulted in upwards of a 10 percent performance improvement--with the improvement being more significant as the test drives increased in size, number of test files, and fragmentation.
Almost every role filled by Windows servers in your computing environment will benefit from the use of disk defragmentation software.
The already high-speed disk defragmentation tool defragments hard drives up to 200 percent faster than previous System Mechanic versions and up to 10 times faster than the Windows defragmenter.
With over 95% corporate market share, Diskeeper has long been recognized as setting the standard in enterprise disk defragmentation. This newest release continues the tradition with a completely new user interface, revolutionary multi-terabyte drive defragmentation and a full-featured administrative console with advanced reporting and alerting features.
In addressing the product's features, the CNET review reported, "We also like the new boot-time defragmenter, which supplements rather than replaces SM5P's Disk Defragmentation Wizard.
Auslogics Disk Defrag was named the best disk defragmentation tool on CNET and other resources.
In addition to hard disk defragmentation, Auslogics Disk Defrag Professional provides expanded HDD and SSD optimization functionality, advanced customization options, reports and visual graphs giving detailed information on each operation's progress and results.
Auslogics Disk Defrag Professional is a program that offers advanced disk defragmentation and optimization algorithms both to home and business users.
All this makes Disk Defrag one of the most popular and trusted disk defragmentation utilities available today.
Its PerfectDisk line of disk defragmentation and optimization software is Windows[R] Certified by Microsoft[R].