Over time our company has acquired a few other companies, and each one of them had their own FTP server. We are now looking into consolidating all the user accounts and data into one, but keeping multiple frontends, spread over Europe, to provide some resilience and also to give better upload/download speed to customers and suppliers. We have high speed Internet connections in all locations, so central storage of all the data isn't an issue (and as we have redundant connections in all locations, an individual line going down isn't an issue either).
I am looking for the best way to have central admin over all the user accounts, for 3 or more frontend servers. In another post here I found a possible solution (proftpd with a mysql backend), but I am wondering whether there are other options.