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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.
This article is provided by FOLDOC - Free Online Dictionary of Computing (


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.
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References in periodicals archive ?
On the supply side, the industry will need to defragment care delivery to promote better outcomes, prevention and early detection, and condition self-management.
We ran each set of tests for three iterations, and then defragmented the storage using Diskeeper to reduce or eliminate the disk fragmentation.
Our local hospital system is spending lots of money to defragment care in our community, which makes practice so much easier, makes patient care more accessible and cost effective, and makes for more informed treatment for all specialties represented ("Quick Clinics: At a CVS Near You!" Jan.
Most people who work with technology on a regular basis have heard so many terms: bits, boot disk, megahertz, driver, defragment, parallel port.
QI want to defragment my computer but I have been told to close all my applications and screen saver beforehand.
Uninstall any unwanted trial software you may have installed, delete any unnecessary e-mail and other junk, and run disk cleanup and defragment.
And just like my computer needs time to defragment to work more effectively, a good run allows me time to process my thoughts and return with a clear head and revitalized.
Another really good time to defragment your hard drive is right after deleting a large amount of files, or uninstalling a group of programs.
I recommend you set your paging file to a fixed size (instructions in the online article) so you can defragment and keep it that way.
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 "Restructuring Hospital Care," Guest Editorial, April 1, 2001, p.
CVM offers features found in VxFS including managing space by concisely mapping files up to a terabyte in size, fast recovery from most system crashes by tracking recent file system metadata updates, online capability to extend and defragment active file systems, and quick I/O features that bypass database kernel locking by treating files as raw partitions.
Microsoft also claims that performance has been improved, reducing the time needed to defragment a hard drive.