Ext3cow is an open-source, versioning file system based on ext3.  It provides a time-shifting interface that allows a real-time and continuous view of the past.  This allows users to access their file system as it appeared at any point in time.  Click here for a usage example.

Ext3cow was designed as a platform for regulatory compliance, and has been used to implement secure deletion, authenticated encryption, and incremental authentication. See the publications page for more details.

Some advantages of ext3cow:

  1. It does not pollute the name space with named versions

  2. It has low storage and performance overhead

  3. It is totally modular, requiring no changes to kernel or VFS interfaces


The ext3cow File System