I read an article on Search Storage entitled Parallel file systems become requirement for HPC environments.
I agree with the author, Deni Connor, that parallel file systems are critical to HPC. It is hard to find a storage vendor selling into the HPC market without a parallel file system story. pNFS will be the mechanism to allow customers to normalize access to parallel file systems, so that they are not forced to deploy clustered file system in every node in their network, whether they wanted that node to serve storage or not.pNFS will give customers the flexibility to choose among parallel file systems, and the entire whole product around them (including Data Protection).
There are a couple points I want to clarify.
First, the article notes:
But the NFS protocol has high overhead, which limits its use with I/O-intensive applications.
In 2006, in a Technical Report written by John Elliot, NetApp disclosed raw I/O performance numbers comparing NFS with iSCSI. Figure 3 of the report is reproduced below.
While the numbers would no doubt be faster today for all storage access protocols, the point is that 10% (as compared to software iSCSI) is not high overhead.
Second, the article states:
pNFS, which is set to be approved by the IETF, draws on Panasas' DirectFlow parallel storage protocol.
The pNFS specification, which is part of the NFSv4.1 specification, was developed by employees (especially those with experience in parallel and clustered file systems) of several companies within IETF's NFSv4 Working Group. (Indeed, these companies will be hosting a BOF at SC08 next week.)
