EMC Celerra HighRoad
EMC Celerra HighRoad or lately renamed MPFS (Multi-Path/Multi-Protocol File System) is a distributed file system. A client-resident agent interacts with the Celerra File Server via a special File Mapping Protocol.
The File Mapping Protocol splits the NFS metadata flow (“Control”) from the data flow which is directly transferred via an iSCSI (MPFSi) or FC (MPFS) link between the client and a Clariion or Symmetrix disk array. All of the file system operations including block allocations, file locking, metadata operation and logging are performed by the Celerra Metadata server, but actual data movement occurs directly between the client and the storage array. By directing data movement to the low latency storage channel, a client realizes line speed data delivery, enabling higher bandwidth than conventional NFS would support. MPFS’s block level data delivery also dramatically reduces the Celerra file server’s workload as the datamovers are not moving data to/from the clients, permitting a large number of clients to share the namespace of a single file server blade. HighRoad/MPFS is a very attractive shared file storage solution for High Performance Computing (HPC) / Grid Computing environments.
MPFS is a combination of patented technology and the NFS protocol, enabling file sharing by hundreds to thousands of client nodes while realizing at least twice higher aggregate bandwidth as compared to conventional NFS file serving, without requiring any application changes. It is a predecessor of the pNFS standard for block devices parallel access. Parallel NFS or pNFS is an attempt to define a standard proposed extension to the NFSv4 protocol in works at IETF.