From Linux NFS
End-Of-Life Notice: This project is now at the end of its lifespan. New features are no longer being developed. The 0.10 branch of fedfs-utils will continue to be updated as security or compatibility issues arise. There is a plan for transitioning some components to other projects.
RFC 5716 introduces the Federated File System (FedFS, for short). FedFS is an extensible standardized mechanism by which system administrators construct a coherent namespace across multiple file servers using file system referrals.
A file system referral is like a symbolic link to another file system share, but it is not visible to applications. It behaves like an automounted directory where a new file system mount is done when an application first accesses that directory. Today, file system referral mechanisms exist in several network file system protocols.
Thus FedFS does not require any change to file system protocols or client implementations. FedFS provides its namespace features using referral mechanisms already built in to network file system protocols.
As a result, FedFS provides network file system namespace configuration to file system clients via network file systems themselves, rather than via side-band protocols like NIS. Clients automatically share a common view of the network file system namespace with no need for individual configuration on each client.
Currently, the Linux FedFS implementation supports only NFS version 4 referrals. More on NFS version 4 referrals can be found in RFC 7530 and RFC 5661. FedFS may support other network file system protocols in the future.
The code provided in this package is a technology preview. The intent is to provide a full and supported Linux FedFS client and server implementation based on this code. Programming and user interfaces may change significantly for the next few releases.
The components in this package are used for managing file system referrals in order to create a global network file system namespace. Installable components include:
- Components to enable Linux NFS clients to discover and mount FedFS domain roots
- Components to enable Linux NFS servers to participate in FedFS domains
- Tools to manage NFSv4 referrals on Linux NFS servers
- Tools to administer FedFS domains
The INSTALL file in this distribution explains more about how to build these components, and which of these components to install on what systems.