Purdue University

Information Technology at Purdue (ITaP) is upgrading the research computing archival storage system Fortress. Currently based upon EMC's DiskXtender (DXUL), Fortress is being upgraded to new, more powerful software: the High Performance Storage System (HPSS).

Data currently in the DiskXtender archive will be migrated transparently to the new system this fall. Benefits include increased transfer speed when using parallel FTP (PFTP) and the ability to provide scalable capacity and I/O performance.

WHAT IS HPSS?

HPSS is the result of over a decade of collaboration among five Department of Energy laboratories and IBM, with significant contributions by universities and other laboratories worldwide.

HPSS provides highly flexible and scalable hierarchical storage management that keeps recently used data on disk and less recently used data on tape. HPSS uses cluster, LAN, and/or SAN technology to aggregate the capacity and performance of many computers, disks, and tape drives into a single virtual file system of exceptional size and versatility. This approach enables HPSS to easily meet otherwise unachievable demands of total storage capacity, file sizes, data rates, and number of objects stored. HPSS provides a variety of user and filesystem interfaces ranging from the ubiquitous vfs, ftp, CIFS, and NFS to higher performance pftp, client API, local file mover, and third party SAN (SAN3P).

WHY MOVE TO HPSS?

The reason for the move is two-fold. - DiskXtender is no longer supported by EMC as of August 11, 2011.

• Purdue's research data archive use increased five-fold in the past five years and it was determined that Purdue's usage pattern was reaching the limits of what our installation of DiskXtender could accommodate, especially in the areas of stability and the ability to access the archive at speeds now possible with modern networking and hardware. WHAT DOES THIS MEAN FOR ME?

For the most part, it means quicker, more robust, and more secure access to the archive. HPSS is very modular and is able to bring the power of multiple servers to bear on any data flow bottlenecks. After the transition, data will continue to be accessible in the new archive system. DiskXtender tapes will be readable by the new system, so only the metadata associated with your files will be converted to HPSS format. The conversion process and testing is currently in progress and scheduled to be completed this summer to ensure that all your files will be available after the transition.

IS ANYTHING DIFFERENT ABOUT HOW I ACCESS MY DATA?

Yes. Some protocols will not be supported in the new system.

• Plain-text FTP will NOT be supported, as this is a security risk that Purdue's security policies no longer allow. In its place, we will have the more powerful PFTP, which is both secure and parallelizes data transfers so that the full network bandwidth can be utilized.
• NFS mounting is supported, but will be limited to RCAC cluster front-end hosts and certain RCAC assets where it is deemed essential because there is the potential for NFS calls to cause performance issues. NFS mounts outside of the rcac.purdue.edu domain, such as on departmental systems, will not be supported.
• Access via CIFS, SSH copy, and FTP will remain, although these protocols will be less able to take advantage of the optimization of the new system to parallelize data streams. HOW CAN I FIND OUT MORE?

You can find out more about HPSS on the collaboration's web site: http://www.hpss-collaboration.org/. RCAC will also hold training sessions on using HPSS as the conversion date grows closer, and new online documentation will be created to help with getting to know the system. Notice will be sent about opportunities to attend training sessions.

ITaP is very excited about the new archive offering, and we hope you will find the new system to be useful. As mentioned, we are expecting a fall rollout of the new system, but the exact date is uncertain as yet. Further communications will be forthcoming as we learn more.

If you have any questions about this, please contact us at rcac-help@purdue.edu.