Hi John,
There are a number of third party applications that will help to achieve. These work by scanning the file system and allowing you to report on capacity, growth, file types etc. EG
http://www.ntpsoftware.com/products/ntp-software-file-reporter-software
http://www.jam-software.com/treesize
However if you are using qtree's within your FlexVols and are applying fixed or tracking quotas to them then this will help you narrow down where the increase in capacity growth is occurring within the file system without requiring a third party application. If you want information about the file types and sizes of each directory within a flexvol or qtree then you'll require a third party application for this.
/matt
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