1. In a data collection agent, a computer-implemented method for processing storage information concerning storage entities in a storage area network environment, the computer-implemented method comprising: receiving a data collection policy identifying storage information to be collected concerning a set of storage entities in the storage area network environment; collecting storage information concerning the set of storage entities according to the data collection policy; processing the collected storage information to produce at least one summary record of the storage information for the set of storage entities, the at least one summary record containing a summary of the collected storage information for the set of storage entities calculated according to the data collection policy; and transferring the at least one summary record from the data collection agent to a storage management application for presentation to a user of the storage management application; wherein receiving a data collection policy comprises: receiving a collection level identifying a set of files corresponding to the set of storage entities from which storage information is to be collected; and receiving a collection period value indicating how often to perform collection of the storage information concerning the set of storage entities; wherein receiving a collection level corresponding to the set of storage entities from which storage information is to be collected comprises: receiving at least one of a host collection level, a file system collection level and a file set collection level; and based on the collection level, identifying, as the set of storage entities, a set of file systems containing at least one file from which storage information is to be collected; wherein collecting storage information concerning the storage entity according to the data collection policy comprises: detecting occurrence of the collection period; in response to the occurrence of the collection period, parsing the set of file systems to query each of the at least one files within directories in the set of file systems identified based on the collection level to obtain file metadata associated with each file; and based on the file metadata for each file detected in each of the set of file systems during parsing, collecting the storage information related to ages and sizes of files and directories for each storage entity associated with at least one of the host collection level, the file system collection level and a file set collection level.