Defragment drive containing Sparse files

  • Thread starter Thread starter Brad Peters
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Brad Peters

I have a sparce file on my machine that is about 3GB in size (not on
disk) when I defragment the drive (using the defrag with win2000) the
file becomes corrupted and all the data in the file is out of place or
missing.

Does anyone have any idea why or perhaps a solution?

Thanks

Brad Peters
 
Brad,

This is very strange. No disk defragmenter (other than SpeedDisk under NT4
and Win2k) actually "moves" files. We all request - via Microsoft's defrag
APIs - to have a file moved from one set of logical clusters to another set
of logical clusters and it is the file system itself that actually performs
the file move - returning control back to the defragmenter when finished
with a success of failure status. In all my years of dealing with
defragmentation and the file system, there has only been 1 instance where
actual file system corruption has occured using Microsoft's defrag APIs.
That was a pre-release version of Windows 2000 (I believe RC2) and it dealt
specifically with FAT drives over 4GB in size. Other than that, the file
move code is very safe and I can't imagine that the defrag process is what
is actually corrupting that file. There are no problems with "moving"
compressed files, sparse files, file with multiple data streams, etc...

- Greg/Raxco Software
Microsoft MVP - Windows Storage Management/File System

Disclaimer: I work for Raxco Software, the maker of PerfectDisk - a
commercial defrag utility, as a systems engineer in the support department.
 
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