Check the actually usage for that site by running the du command for that directory, .eg.
du -sh directoryname
or to get a summary of each directory/file
du -sh *
Sometimes the cobalt panels do not correctly report disk usage.
Check for anonymous ftp. pojo is correct in that when warez distributors discover anonymous ftp, your bandwidth and server can quickly become overloaded. Your servers IP and the list of files available circulate the internet very quickly via newsgroups. Look in all of your ftp site folders for a possible warez dump. Also, people use similar techniques to distribute movies and pornography.
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