Are files being opened or saved to the server during
defrag?
Perform the defrag at a time when nobody is accessing the
server. (i.e. overnight, weekend, etc.)
A drive must have at least 15% free space for defrag to
completely and adequately defragment it.
You cannot defragment drives that have any file system
corruption. Run CHKDSK first to check the drive.
Austin M. Horst