# Migration to the new enhanced GPFS work file system

a new GPFS scratch file system, based on IBM GPFS Storage Server (GSS) infrastructure will be taken into production to

• double the performance,
• achieve extreme data integrity,
• accelerate rebuild times with minimal performance impacts,
• and thereby enhance data protection.

Because of the huge amount of data and the enormous number of files in $WORK it is not reasonable to pre-copy all data into the new file system. Your active help is needed to copy the data you want to keep, using the standard Unix command "cp". Please read the following work plan carefully and follow it thoroughly: 1) Since August 2013 the new optimized file system referenced by the environment variable$WORKNEW is available.

It is recommended to start using the $WORKNEW file system for scratch data at the HPC systems (JUQUEEN, DEEP). Quotas for projects/groups are preserved during the transition from$WORK to $WORKNEW. 2) On September 16, 2013, the$WORKNEW file system will become the standard scratch file system and the environment variable $WORK will be switched to reference this new filesystem. So$WORKNEW and $WORK reference the same (new) file system.The old file system will now be only accessible via the environment variable$WORKOLD and it is set to READ-ONLY!

Jobs referencing data which were not yet been transferred, will have to be changed.

August 2013ab 16. September 2013
/work rw $WORK-->/workold ro$WORKOLD
/worknew rw $WORKNEW-->/work rw$WORK, $WORKNEW 3) On January 2014, the file system referenced as$WORKOLD will be deleted as it should be empty after 90 days by the normal cleanup routine.

Some further remarks:

• At JUROPA the environment variables $GPFSWORK,$GPFSWORKNEW, and $GPFSWORKOLD will be set on the GPFS nodes accordingly, so you might need to adapt your scripts. • As before, data that are older than 90 days and not accessed for 90 days will be deleted automatically as well as empty directories are already deleted after 3 days automatically. • As before there is no backup for data stored in$WORK, $WORKNEW,$WORKOLD.

Thank you in advance for your help. We are firmly convinced that the planned rearrangements will make access to data on the GPFS scratch file system more effective.

If you need some extra information please feel free to contact

SC-support at Juelich Supercomputing Centre
Email: sc@fz-juelich.de
Phone: +49-2461-61-2828