Command: defrag
DEFRAG optimizes file loading times from a disk by moving file
fragments together.
Syntax:
defrag [/C] [drive] [{/F|/U|/DF|/FF|/FD}] [/Sorder[-]] [/B] [/X] [/A]
[/FO] [/?]
drive This is the drive letter of the drive you wish to
defragment. For instance: defrag c:
Options:
/C Use command line version only. Defrag will not use its
menu-driven user interface if you use this option. It will
communicate through the command line instead.
You must use the [drive] option, as described above,
when you use the /C switch, e.g. defrag /c c:
/F Fully optimizes specified drive. With this option, defrag will
perform a full optimization by making sure that all files are
at the beginning of the disk, with no gaps in between.
/U With this option, defrag will unfragment the files, but
gaps may be left between files.
/FF Fully optimized the drive, moving all files first.
/DF Fully optimized the drive, moving all directories first.
/FD Fully optimized the drive, moving all files of the same directory
together.
/S Sort files by specified order.
order: N by Name (alphabetic)
E by Extension (alphabetic)
D by Date and time (earliest first)
S by Size (smallest first)
- suffix to sort in descending order.
/B Reboots the computer after the optimization.
/X Forces defrag to exit as soon as it completes the optimization.
/A For use with the /C option, defrag will give an audible warning
before taking action.
/FO For use with the /C option, this tells defrag to give a more full
output of information.
/? Shows the help.
Comments:
Type DEFRAG /no-ops for a list of no-ops (/SKIPHIGH, /LCD, /BW, /GO).
Type DEFRAG /contrib for a list of contributors.
It is recommended to use DEFRAG with the user interface (not: /C).
What is disk fragmentation?
When files are deleted, or made smaller, this leaves gaps in the data
stored on the disk. If a file is created, or increases in size, it will
go in the gaps, but if this space isn't big enough, the file will be
continued elsewhere on the disk. After many such operations the file
data can become very scattered. This fragmentation process slows down
file access. Fragmentation is a normal process on DOS disks.
When should I use defrag?
Use defrag occasionally, or after installation of larger programs or
after the creation of many (small) files.
DEFRAG has the following EXITCODES (ERRORLEVEL):
0 success
1 internal error
2 disk too full to defrag
3 aborted by user
4 general error
5 read error
6 write error
7 FAT allocation error
8 memory error
9 out of memory
Examples:
defrag c: /F
See also:
chkdsk
dosfsck
(scandisk)
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Copyright (C) 2003 - 2004 Robert Platt, updated 2011 by W. Spiegl.
This file is derived from the FreeDOS Spec Command HOWTO.
See the file H2Cpying for copying conditions.