Q94357: Difference Between DEFRAG and DBLSPACE /DEFRAGMENT

Article: Q94357
Product(s): Microsoft Disk Operating System
Version(s): MS-DOS:6.0,6.2,6.22
Operating System(s): 
Keyword(s): 
Last Modified: 16-NOV-1999

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The information in this article applies to:

- Microsoft MS-DOS operating system versions 6.0, 6.2, 6.22 
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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---------------- ] " (without the quotation marks)

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------- ] " (without the quotation marks)

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------- ] " (without the quotation marks)

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:

1. Run DBLSPACE to defragment the CVF.

2. Move all the sectors to the end of the disk by typing the following at the
  MS-DOS command prompt:

  " dblspace /defragment /f " (without the quotation marks)

3. Run Defragmenter with the /F parameter by typing the following at the MS-DOS
  command prompt:

  " defrag /f " (without the quotation marks)

  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.

Additional query words: 6.00 6.20 dblspace double space defrag

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Keywords          :  
Technology        : kbMSDOSSearch kbMSDOS622 kbMSDOS620 kbMSDOS600
Version           : MS-DOS:6.0,6.2,6.22

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