• kfdi-exs-1.0a Released! (Aug. 2004)
  The first public release and an alpha version of KFDI and EXS file system.

KFDI is an interface between file systems and databases in the Linux kernel. It establishes a bridge between conventional hierarchy file systems and relational databases, so that these two kinds of storage technologies can cooperate in data management.

Taking advantage of relational database technology and XML, KFDI enables users to manage their data in a more flexible and efficient way. Files can be searched by data properties. KFDI also introduces some object-oriented concepts into file organization.

KFDI is an open framework over the Linux VFS layer. Any file system can request KFDI services, and KFDI is transparent to the file systems not supporting it. In fact, many existing file systems can be easily modified to support KFDI.

Though currently KFDI is primarily backed by PostgreSql, it is possible to use other database engines, even a center database server in a distributed environment.

EXS is an example file system that supports KFDI. The name "EXS" implies three involved technologies: ext2 file system, XML and SQL database.

EXS is derived from the ext2 file system. Actually, the modification is very small.