Difference Between DEFRAG and DBLSPACE /DEFRAGMENT (94357)
The information in this article applies to:
- Microsoft MS-DOS operating system 6.0
- Microsoft MS-DOS operating system 6.2
- Microsoft MS-DOS operating system 6.22
This article was previously published under Q94357
This information applies to both Microsoft DoubleSpace and Microsoft
DriveSpace. For MS-DOS 6.22, use DRVSPACE in place of DBLSPACE for commands
and filenames.
SUMMARY
There are two ways to defragment a DoubleSpace drive: you can run
DBLSPACE /DEFRAGMENT, or you can run Microsoft Defragmenter
(DEFRAG.EXE).
MORE INFORMATION
Files stored on DoubleSpace drives become fragmented just as they do
on physical drives.
Running DEFRAG.EXE
Microsoft Defragmenter (DEFRAG.EXE) makes files contiguous by making
virtual clusters contiguous. For example, a DoubleSpace drive would
change from
H:\DBLSPACE.000: [1213--542---132-2--113---4 ]
C: [1123156-1-13-5-1-2-3-1521--123------- ]
to:
H:\DBLSPACE.000: [1213--542---132-2--113---4 ]
C: [111112222333344455556---------------- ]
NOTE: In this example, each number represents a piece of a file. For
example, each "1" indicates a piece of file 1.
Running DBLSPACE /DEFRAGMENT
DBLSPACE /DEFRAGMENT moves data within the compressed volume file
(CVF) so that all the free space is at the end. Files aren't made
contiguous; they are simply placed in one group at the front of the
drive. Using the same example, the file would change from
H:\DBLSPACE.000: [1213--542---132-2--113---4 ]
C: [1123156-1-13-5-1-2-3-1521--123------- ]
to:
H:\DBLSPACE.000: [121354213221134----------- ]
C: [1123156-1-13-5-1-2-3-1521--123------- ]
Running DBLSPACE /DEFRAGMENT /F
DBLSPACE/DEFRAG/F moves all the used sectors to the end of the CVF.
Using the same example, the file would change from
H:\DBLSPACE.000: [1213--542---132-2--113---4 ]
C: [1123156-1-13-5-1-2-3-1521--123------- ]
to:
H:\DBLSPACE.000: [-----------121354213221134 ]
C: [1123156-1-13-5-1-2-3-1521--123------- ]
NOTE: When you run DBLSPACE with the /DEFRAGMENT parameter, it may not
make all of the unused sectors contiguous; this is why the /F switch
exists. If you cannot resize a DoubleSpace drive because it is too
fragmented, you must defragment the drive with DBLSPACE /DEFRAGMENT
and then with Defragmeter.
To do this:
- Run DBLSPACE to defragment the CVF.
- Move all the sectors to the end of the disk by typing the following
at the MS-DOS command prompt:
- Run Defragmenter with the /F parameter by typing the following at
the MS-DOS command prompt:
This should move all of the data to the end of the CVF and then back to
the front. All of the unused sectors should then be contiguous.
Fully Optimizing Your DoubleSpace Drive
If you type DEFRAG to defragment a DoubleSpace drive, Defragmenter
runs DBLSPACE /DEFRAGMENT when it has completed. Once both types of
defragmentation have been done, the sample file appears similar to
the following:
H:\DBLSPACE.000: [121354213221134----------- ]
C: [111112222333344455556---------------- ]
Note that files are contiguous on the virtual drive (drive C) but not
within the CVF. Free space is contiguous in both places.
Modification Type: | Major | Last Reviewed: | 11/16/1999 |
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Keywords: | KB94357 |
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