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(tool, file system)
/dee-frag(-ment)'/ (Or "defrag") To coalesce files and free space on a file system; to reduce fragmentation.


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
Diskeeper is one of the most popular defraggers on the market. The red in the drive map at the top shows all the fragmented files. After defragmenting, the new drive map was pasted on the bottom for comparison. 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.
References in periodicals archive ?
When you first install Diskeeper, Executive Software recommends you defragment once, then run the boot-time defrag as needed to get the master file table (MFT), directory, and paging files contiguous.
Diskeeper defragments a disk significantly more thoroughly and from 300 percent to 500 percent faster than the disk defragmenter included in the Windows 2000 operating system.
Defragment your hard disk: Defragmenting the hard drive is an effective way to restore the quick response of your system.
The recent period was the changing for the country due to the fomenting seditions and feuds which risked to defragment the social texture, he added, noting that tense atmospheres are detrimental to legislative action.
2) Defragment your hard drive: As you use your computer - install, uninstall, add and delete - the hard drive can get the digital equivalent of a messy garage.
Q I HAVE been trying to defragment my computer, but I get the following message: Your computer does not have enough free memory to defragment this drive (C).
Time to defragment the disk (put the files remaining into some kind of congruous order so your computer isn't jumping all over the hard drive looking for them.
You now have three options: You can click on Check Now, which will perform the tasks formerly performed by ScanDisk; you can click on Backup Now, which, as the name implies, backs up files; or you can click on Defragment Now, which will defrag the files on the disk and, as a result, speed up your computer.
With businesses losing up to $50 billion each year due to the failure to defragment all of their computers, using a networkable defragmenter like Diskeeper, according to reports released by IT analysts at IDC, Diskeeper provides a cost-effective way to increase productivity and increase return on investment.
Wachter suggested that the explosion of the hospitalist movement onto the American health care scene was ignited by the need to defragment hospital care and by the Institute of Medicine's call for a wholesale restructuring of the American health care system ("Defragmenting Hospital Care," Guest Editorial, April 15, 2001, p.
Another suggestion, which I now am rethinking, is to defragment the drives being backed up.