Andrés J. Díaz


Patches for linux kernel and nfs-utils to support multiple server in mount point and failover when one of them becomes unreacheable. Only works in read-only mode.

This project has no releases. Read README file for more information about how to use this project.




NFS3 Failover is part of big project were I was working during 2010 in order
to manage a large fleet of physical hosts. To keep some files in-sync with all
nodes in the system, I use NFS3 in read-only mode.

While the master nodes provides the content of that files, the slaves
nodes just mount the shared directory and read the data.

To keep the system scalable I use a number of masters per slaves,
that is, for example, 4 master nodes per 40 slaves nodes. Unfortunately
mainline version of nfs3 modules (sunrpc, actually) and mount binaries
do not support failover for NFS3 (NFS4 includes failover by design). In
order to enable this capability, we need to implement failover
functionality for nfs3 in kernel modules and moun options.

Most of the work was done by my colleage Manuel Sanmartín, I just
adapt these patches to run in modern linux versions and new mount

This repository contains submodules to patched kernel sources (linux/
directory) and nfs-utils patched sources (nfs-utils/ directory).

To install patched sources you need to recompile kernel and nfs-utils as

  cd linux/ && make menuconfig && make && make modules_install && make install
  cd nfs-utils/ && ./configure && make && make install


If you find any error in the code or incorrect behaviour, please do not hesitate to report me at ajdiaz+nfs3-failover at

The mainstream code is keep under git control, you can clone as usual:

git clone git://

Also you can open a issue in github mirror.


All rights reserved to the respective authors of each project. See COPYING
notes in Linux kernel and in nfs-utils project. NFS3 Failover changes are
disitributed under MIT license if no other licensed can be applied.

Andrés J. Díaz <ajdiaz at>.
GPG Key: 90ADF27A6AA55A789738CDB15369AA4171B5139C. GPG Key Signing Policy.