| The data tsunami that will be caused by data intensive science experiments such as the SKA is high on the agenda of global R&D efforts. As an appetizer, we are now witnessing the onset of LOFAR's contribution to this data tsunami.
The diagram shows the total volume of LOFAR data stored in the Long Term Archive (LTA) since the start of LOFAR CS1 operations in 2007. After a steady but 'modest' growth in the childhood years of LOFAR a dramatic increase is seen since early this year. The increase is linked to the majority of the planned LOFAR stations now being operational and to the roughly fourfold increase of data producing capability of the Central Processing cluster upgrade (Daily Image 20-4-2011).
The total volume of nearly 700 Terabytes now stored in the LTA is the equivalent of roughly 14,000 Blu-ray DVD's or 80,000 old fashioned dual-layer DVD's. Over the first four months of this year, LOFAR has stored more data at SARA than the ATLAS and LHCb High Energy Physics experiments together and at the current rate a volume equivalent to the archive of 40 years of WSRT observational data is stored in the LTA every eleven days.
The LOFAR LTA takes care of the storage, distribution, and analysis of LOFAR data once it has left the care of the Central Processing cluster. It is a distributed system that involves sites in Amsterdam hosted by SARA as part of the BiG Grid infrastructure, in Jülich hosted by the Forschungszentrum Jülich as part of the German contribution to the International LOFAR Telescope, and in Groningen hosted by the University of Groningen as part of the Target infrastructure. Up to now, most of the data has been stored at SARA but Jülich has recently become an active site as well and the multi-petabyte Target storage system in Groningen is close to being brought online. Since the growth rate of the LOFAR LTA will only increase in the coming period, the capacity of all sites will be sorely needed soon.