Dual mode use requirements analysis for the institutional cluster.

This paper analyzes what additional costs would be incurred in supporting dual-mode, i.e. both classified and unclassified use of the Institutional Computing (IC) hardware. The following five options are considered: periods processing in which a fraction of the system alternates in time between classified and unclassified modes, static split in which the system is constructed as a set of smaller clusters which remain in one mode or the other, re-configurable split in which the system is constructed in a split fashion but a mechanism is provided to reconfigure it very infrequently, red/black switching in which a mechanism is provided to switch sections of the system between modes frequently, and complementary operation in which parts of the system are operated entirely in one mode at one geographical site and entirely in the other mode at the other geographical site and other systems are repartitioned to balance work load. These options are evaluated against eleven criteria such as disk storage costs, distance computing costs, reductions in capability and capacity as a result of various factors etc. The evaluation is both qualitative and quantitative, and is captured in various summary tables