Patent attributes
A software and hardware facility persistently maintains metrics on directories at different levels within a tree of a filesystem. The facility hierarchically aggregates attributes of files contained by directories and stores them as metric values in each directory within a tree. The stored values represent summed or otherwise aggregated data from the descendant directories and files. The metric values represent aggregated attributes such as total space consumed by a directory and all the descendant directories and files, total number of files within a directory, total data blocks used by a directory and its descendant directories and data files, etc.