8.2. pNFS

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. It supports three storage protocols or layouts: files, objects, and blocks.


The protocol allows for three possible pNFS layout types: files, objects, and blocks. While the Red Hat Enterprise Linux 6.4 client only supported the files layout type, Red Hat Enterprise Linux 7 supports the files layout type, with objects and blocks layout types being included as a technology preview.
To enable this functionality, use the following mount option on mounts from a pNFS-enabled server:
-o v4.1
After the server is pNFS-enabled, the nfs_layout_nfsv41_files kernel is automatically loaded on the first mount. The mount entry in the output should contain minorversion=1. Use the following command to verify the module was loaded:
$ lsmod | grep nfs_layout_nfsv41_files
For more information on pNFS, refer to: http://www.pnfs.com.