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JUST - Juelich Storage Cluster

JUST Cluster (Phase 3)Copyright: FZ Jülich

The Juelich Storage Cluster (JUST) serves as GPFS fileserver (General Parallel File System) for the supercomputing systems JUQUEEN, JUROPA, JUDGE, and some dedicated cluster systems like JUVIS and DEEP at the Juelich Supercomputing Centre (JSC).

JUST holds a local GPFS cluster with different GPFS file systems dedicated to the kind of usage by the users.

  • One part of the cluster is built by classical components like servers, storage controllers, and standard GPFS on top.
  • The second part uses the new GPFS Storage Servers (GSS) with servers, storage JBODS, and GPFS Native RAID which includes the storage controller part into GPFS. Thereby it uses the declustered RAID technology to deliver not only outstanding throughput, but also extreme data integrity, faster rebuild times, and enhanced data protection. See also the IBM case study about GSS at JSC as well as Lenovo case study about GSS at JSC.

Access to the data from the HPC systems is in general realized by Remote GPFS functions, in one case combined with CNFS (Clustered Network File System). Additionally there is a NFS gateway for a special trusted project in cooperation with JSC.

The measured peak performance for applications on JUQUEEN using the fast scratch file system ($WORK) and the dedicated file system ($DATA) on the GSS infrastructure was 160 GB/sec.


Aug 2014Migration of $HOME and administrative file systems from the classical GPFS storage to GSS-24 servers and thereby doubling the capacity of each $HOME.
17 Jun 2014Integration of the file systems of the classical GPFS cluster into the GSS GPFS cluster and conversion of all GPFS file systems to the same latest level (
May/Jun 2014Installation and setup of additional three GSS-24 with about 2.2 PB usable storage for future migration of $HOME file systems to GSS infrastructure.
13 Feb 2014Overall upgrade to GPFS 3.5.x
6./12. Feb 2014JUST3: Old scratch file system deleted;
Final Power OFF of JUST3 GPFS-server and -storage
16 Sep 2013Switch the standard scratch file system to be the one at the GSS infrastructure and offer for a limited time access to the old scratch file system in read-only mode only. See Migration to the new enhanced GPFS work file system
Aug 2013Start production at new scratch file system ($WORKNEW) which will become the standard scratch file system on 16 September 2013. See Migration to the new enhanced GPFS work file system
Jun 2013Provide two new file systems at GSS: /worknew a new scratch file system that will replace the /work file system in the nearby future and /data file system dedicated to large projects in collaboration with JSC and on application for quota only
Jan 2013JUST4-GSS: Installation and test of new limited available GSS (GPFS Storage Server) systems; Additional capacity: 9.2 PB gross, 7.4 PB net
Dec 2012Partial upgrade to GPFS 3.5.x for special mmbackup application
Sep 2012Upgrade to GPFS 3.4.x
May 2012$WORK capacity and performance doubled by adding all freed JUST3 storage controllers
Apr 2012$HOME and $ARCH file systems migrated from JUST3 to new JUST4 storage
Mar 2012JUST4: Expansion of JUST by additional xSeries servers and new storage controller IBM DS3512 and DCS3700; Additional capacity: 4.4 PB gross, 3.4 PB net
Dec 2011End of production for DEISA fileservers
Nov 2010Upgrade to GPFS 3.3.x
Dec 2009JUST3: Expansion of JUST by replacement of storage controller for GPFS-Data part by IBM DS5300; Capacity: 5.6 PB gross, 4.3 PB net
Mar 2009JUST2: Expansion of JUST by replacement of Power5 systems by Power6 systems incl. new IBM DS5300 storage controller for GPFS-Metadata part
Jan 2009Upgrade to GPFS 3.2.x
Jun 2008GPFS cluster for DEISA file systems added on dedicated DEISA fileservers
Jul 2007Start production of JUST: IBM Power5 server systems with IBM DS4800, DS4700, and DCS9550 storage controller; GPFS 3.1.x; Capacity: 1.1 PB gross, 0.86 PB net