  Obtaining high performance in IO intensive applications requires systems that
support reliable fast transfer, data replication, and caching. In this paper we
present an architecture designed for supporting IO intensive applications in
MedioGRID, a system for real-time processing of satellite images, operating in
a Grid environment. The solution ensures that applications which are processing
geographical data have uniform access to data and is based on continuous
monitoring of the data transfers using MonALISA and its extensions. The
MedioGRID architecture is also built on Globus, Condor and PBS and based on
this middleware we aim to extract information about the running systems. The
results obtained in testing MedioGRID system for large data transfers show that
monitoring system provides a very good view of system evolution.
