There are a number of NT disk defraggers on the market, including
Winternals Defrag Manager. These tools are useful for performing a
general defragmentation of disks, but while most files are defragmented
on drives processed by these utilities, some files may not be. In
addition, it is difficult to ensure that particular files that are
frequently used are defragmented - they may remain fragmented for
reasons that are specific to the defragmentation algorithms used by the
defragging product that has been applied. Finally, even if all files
have been defragmented, subsequent changes to critical files could cause
them to become fragmented. Only by running an entire defrag operation
can one hope that they might be defragmented again.
Contig is a single-file defragmenter that attempts to make files
contiguous on disk. Its perfect for quickly optimizing files that are
continuously becoming fragmented, or that you want to ensure are in as
few fragments as possible.
Using Contig
Contig is a utility that defragments a specified file or files. Use it
to optimize execution of your frequently used files.
Set valid data length for quick file creation (requires administrator rights)
-q
Quiet mode
-s
Recurse subdirectories
-v
Verbose
Contig can also analyze and defragment the following NTFS metadata
files:
$Mft
$LogFile
$Volume
$AttrDef
$Bitmap
$Boot
$BadClus
$Secure
$UpCase
$Extend
How it Works
Contig uses the native Windows NT defragmentation support that was
introduced with NT 4.0 (see my documentation of the defrag APIs for more
information). It first scans the disk collecting the locations and sizes
of free areas. Then it determines where the file in question is located.
Next, Contig decides whether the file can be optimized, based on free
areas and the number of fragments the file currently consists of. If the
file can be optimized, it is moved into the free spaces of the disk.
More Information
Helen Custer's Inside Windows NT provides a good overview of the
Object Manager name space, and Mark's October 1997 Windows NT Magazine
column,"Inside the Object Manager", is (of course) an excellent
overview.
This module explores file system fragmentation and the tools that you can use to reduce fragmentation. Students will learn how Windows can compress files to take up less space on the hard disk.