file compression and disk defrag

[RGivens]

Does file compression effect disk defragmentation? I have
a server with a 300GB data partition. It has about 60GB's
of free space, but a considerable amount of the files
stored on the partition are compressed to conserve space.
When I go to defrag the partition it says I only have 12%
free to use for the defrag and try to free up more space
because you need about 20% to do a good defrag. I have
Executive Softwares Diskeeper installed that runs defrag
during non-business hours on a Windows 2000 SP4 server.
Diskeeper is running but doesn't appear to be doing a
thing to the level of fragmentation so I was wondering if
it's because of the large amount of compressed files on
the machine.

Thank you.

 

[Greg Hayes/Raxco Software]

Yes, With Windows 2000, when a compressed file is "moved" during the defrag
process, the file is first uncompressed and then re-compressed.

Free Space on NTFS drives is located in 2 different areas - inside and
outside of the MFT Reserved Zone. Microsoft's defrag APIs under Windows
2000 do not let defragmenters use the free space inside.

There is no technical reason why you should need 20% free space in order to
defrag. That high of a free space requirement is common to "old-fashioned"
defragmenters. It is possible to defragment with as little as 5% if you use
a different tool

- Greg/Raxco Software
Microsoft MVP - Windows File System

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

Want to email me? Delete ntloader.