27 March 2020

DAS-4/VU and DAS-4/Delft have been decommisioned. The role of for password updates has been taken over by For access to old data on DAS-4/VU or DAS-4/Delft, mail

5 April 2018

OpenNebula on DAS-4/VU and DAS-4/Delft has been updated to version 5.4.6.

4 April 2018

The DAS-4 clusters have been updated to CentOS 7, and the Nvidia CUDA development kit has been updated to version 8.0 (version 9.1 is also available for recent GPUs). This update makes DAS-4 software-compatible with DAS-5.

6 Jul 2015

DAS-5 is now fully operational! To make room for DAS-5, DAS-4/UvA and DAS-4/ASTRON have been decomissioned, only their headnodes remain available.

DAS-4 clusters

DAS-4 includes roughly 200 dual-quad-core compute nodes (primarily SuperMicro 2U-twins with Intel E5620 CPUs), spread out over six clusters, located at five sites. The system has been built by ClusterVision. Like its predecessor, DAS-3, DAS-4 is rather heterogeneous in design:

Cluster Nodes Type Speed Memory Storage Node HDDs Network Accelerators
VU 74 dual quad-core 2.4 GHz 24 GB 30 TB 2*1TB IB and GbE 16*GTX480 + 2*C2050
LU 16 dual quad-core 2.4 GHz 48 GB 50 TB 5*2TB + .5TB SSD IB and GbE future upgrade (FPGAs)
UvA 16 dual quad-core 2.4 GHz 24 GB 30 TB 1TB IB and GbE future upgrade
TUD 32 dual quad-core 2.4 GHz 24 GB 18 TB 2*1TB IB and GbE 8*GTX480
UvA-MN 36 dual quad-core 2.4 GHz 24 GB 30 TB 2*1TB IB and GbE 8*GTX480 + 7*C2050 + 2 x GTX480
ASTRON 24 dual quad-core 2.4 GHz 24 GB 24 TB 1*1TB IB and GbE 8*GTX580 + 1*C2050 + 1*HD6970

Besides using the ubiquitous Ethernet (1 Gbit/s at the compute nodes, 10 Gbit/s on the head nodes), DAS-4 also employs the high speed InfiniBand interconnect technology. Quad Data Rate (QDR) InfiniBand (IB) is used as an internal high-speed interconnect, but also to connect with the other DAS-4 clusters by means of routers that communicate over dedicated 10 Gbit/s Ethernet lightpaths. These lightpaths are implemented via a fully optical (DWDM) backbone in the Netherlands, SURFnet6. See also: DAS-4 Connectivity.

The operating system the DAS-4 runs is CentOS Linux. Cluster management is done using Bright cluster management suite. In addition, software from many sources is available to support research on DAS-4: the Grid Engine resource management system, various MPI implementations (e.g., OpenMPI and MPICH), optimizing compilers, visualization packages, performance analysis tools, etc.

DAS-4 is a very actively used research tool for experimental Computer Science in the Netherlands, as also witnessed by the special hardware (new node types, accelerators, storage) that has been added to the above list since the start of the project.