Robinhood Policy Engine is a multi-purpose tool for managing the content of large filesystems. It can audit filesystem content, perform accounting, remove old unused files according to admin-defined policies, show customizable alerts based on file properties, backup data to external storage, and more. It has advanced capabilities for Lustre filesystems. It leverages OST usage, and lists or purges files per OST, with policy criteria based on pools and OST index. It can also process MDT changelogs with Lustre v2. Originally developped for HPC, it has been designed to perform all of its tasks in parallel, so it is particularly adapted for running on large filesystems with millions of entries and petabytes of data. But you can nonetheless take advantage of all of its features for managing smaller filesystems.
DFF (Digital Forensics Framework) is a simple but powerful tool with a flexible module system which will help you in your digital forensics works, including file recovery due to error or crash, evidence research and analysis, etc. DFF provides a robust architecture and some handy modules.