Monday, November 21, 2011

NetApp has shipped its pNFS server

This week is Thanksgiving in the USA, and today the NFS industry has much to be thankful. Because today, Release Candidate 2 of Data ONTAP 8.1 was posted to NetApp's site and is available for download now. Release Candidate 2 introduces NetApp's pNFS server for Data ONTAP Cluster Mode, as well as the NFSv4.1 server necessary to enable pNFS functionality. This pNFS server supports the files-based layout type, aka LAYOUT4_NFSV4_1_FILES.

As described in Red Hat's documentation, the RHEL 6.2 beta release includes a tech preview of RedHat's upcoming pNFS client for Linux. You can also go the Fedora route.

Two questions that we often get about our pNFS server are:
  1. Is there is a single pNFS metadata server? Answer: no, every node in a Data ONTAP 8 Cluster Mode storage cluster is capable of being a metadata server. The NFSv4.1 client simply NFS mounts a volume via any node of the storage cluster, and that node acts as a metadata server.
  2. What happens when a node hosting a metadata server encounters a failure? The Data ONTAP 8 Cluster Mode system is designed to be fault tolerant if there are two or more nodes in the cluster. Another node will be assigned the network interfaces (essentially, IP addresses) of the failed node, and the NFSv4.1 client will re-connect to the new node, discovering that there has been a metadata server failure, and if necessary, obtain new layouts to any open files that were being accessed over pNFS.
Enjoy NetApp's pNFS server, and have a great Thanksgiving.