Defragment

1 definition found

From The Free On-line Dictionary of Computing (27 SEP 03) [foldoc]:

  defragment
       
           /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%.
       
          (1997-08-29)