Support for Parallel NFS (pNFS) as part of the NFS v4.1 standard is available as of Red Hat Enterprise Linux 6.4. The pNFS architecture improves the scalability of NFS, with possible improvements to performance. That is, when a server implements pNFS as well, a client is able to access data through multiple servers concurrently. The pNFS protocol supports three storage protocols or layouts: files, objects, and blocks. Red Hat Enterprise Linux 6.4 supports only the "files" layout type.

To enable support for pNFS functionality, use one of the following mount options on mounts from a pNFS-enabled server:

-o minorversion=1

or

-o v4.1

Set the permissions of the pNFS path so that Red Hat Enterprise Virtualization can access them:

# chown 36:36 [path to pNFS resource]

After the server is pNFS-enabled, the nfs_layout_nfsv41_files kernel is automatically loaded on the first mount. Verify that the module was loaded:

$ lsmod | grep nfs_layout_nfsv41_files

Another way to verify a successful NFSv4.1 mount is with the mount command. The mount entry in the output should contain minorversion=1.