The water fountain vs. the fire hose: an examination and comparison of two large enterprise mail service migrations
Craig Stacey, Max Trefonides, Tim Kendall, Brian Finley · 2009
Mail administrators will inevitably face a situation where they will need to migrate their users from one server to another, not infrequently migrating to a different service altogether. In 2008, two divisions of Argonne National Laboratory found themselves needing to migrate their users from disparate divisional mail servers to a central, institutional Zimbra Collaboration Server. Each group approached the situation from a different direction, driven by different motivations, timelines, and external forces; each ultimately achieved its goal, one more smoothly than the other. The first migration was driven by a high sense of urgency resulting in a “fire hose ” approach, an en masse move followed by a grand switchover; the second migration was a more measured “water fountain ” approach, taking in lessons learned during the first migration. Examining the processes, decisions, and tools used in each conversion yields a roadmap of successes and pitfalls that should prove useful to any systems administrators facing a similar task, regardless of the timeline within which they must work.