by Michael Ewan
This paper discusses recent (Originally Published On January 23, 2009) research and testing of clustered, parallel file systems and object storage technology. Also included is an overview of product announcements from HP, IBM and Panasas in these areas.
The leading data access protocol for batch computing is currently Network File System (NFS), but even with bigger, faster, more expensive Network Attached Storage (NAS) hardware available, batch processing seems to have an insatiable appetite for I/O operations per second. The national labs have seen this NFS bottleneck in their high-performance computing (HPC) clusters and have abandoned NFS in favor of Lustre* at Pacific Northwest National Lab (PNNL) and Lawrence Livermore National Lab (LLNL). LLNL and Los Alamos National Lab (LANL) have adopted Panasas hardware-based object storage. This paper details the research and testing of clustered, parallel file systems with applications to batch pool HPC methodologies and discusses object storage technology. It also discusses recent product announcements from HP, IBM, and Panasas in these areas.
During the research, the following file systems were investigated:
* Global File System* (GFS*) from Sistina (now Red Hat)
* General Parallel Files System* (GPFS*) from IBM
* iSCSI aggregation* from Terascale
* Parallel Virtual File System* (PVFS*) and PVFS2* from Clemson University
* Lustre from Cluster File Systems
Out of this investigation, a lab test of PVFS2 and Lustre based on scalability and access criteria was performed. This paper details those selection criteria and test results, plus features of each file system explored.
Two interesting emerging technologies are object storage devices and iSCSI. The Lustre parallel file system and Panasas both use object storage devices (called targets in Lustre). This paper describes object storage devices as well as storage aggregation using PVFS and iSCSI. What if by using either object storage targets in Lustre or storage aggregation, one could make use of all the excess storage in each compute node, simultaneously and in parallel? In a normal e-commerce (EC) environment, the available (free) storage would be on the order of 30 to 100 terabytes, dependent on disk size and number of compute nodes.