Search in: Word
Vietnamese keyboard: Off
Virtual keyboard: Show
Computing (FOLDOC) dictionary
Jump to user comments
tool, file system /dee-frag(-ment)'/ (Or "defrag") To
coalesce files and free space on a file system.
As modern file systems are used and files are deleted and
created, the total free space becomes split into smaller
non-contiguous blocks (composed of "clusters" or "sectors"
or some other unit of allocation). Eventually new files being
created, and old files being extended, cannot be stored each
in a single contiguous block but become scattered across the
file system. This degrades performance as multiple seek
operations are required to access a single fragmented file.
Defragmenting consolidates each existing file and the free
space into a continuous group of sectors. Access speed will
be improved due to reduced seeking.
The rate of fragmentation depends on the algorithm used to
allocate space and the number and position of free sectors. A
nearly-full file system will fragment more quickly.
MSDOS and Microsoft Windows use the simplest algorithm to
allocate free clusters and so fragmentaton occurs quickly. A
disk should be defragmented before fragmentation reaches 10%.