Charles - I would regard this as an outgrowth issue, where the amount of data has outgrown the now-very-old Windows 2000 operating system within which the data lives. W2K is known to have a variety of memory address capacity issues. Nature is telling your shop that it is time for that data to live under a modern operating system, with the capacity to handle it.
The other, best alternative is to subdivide the file system. Partitions are good things, to help better organize data and limit the impact of damage to any one file system (logical corruption, media surface damage, etc.). Too many work groups think that creating a single file system on a very large disk is a great implementation approach, without realizing the ramifications. IT groups should guide such departments in best disk utilization, to prevent whimsical, problematic implementations. Richard Sims