What was the technology stack driving the original Ultima Online servers?
Wow they didn't use any DB at the start of UO, that is amazing haha"As Raph also notes, there were no databases originally involved in the storage of game state or player data for UO (disregarding analytics here), everything was kept in flat files. Backups worked by flagging a moment in time where no one was allowed to cross server-boundaries -- during that moment, each areaserver was commanded to fork(), essentially duplicating itself in memory (it's more complicated than this, thanks to Copy-on-Write, but let's simplify). After everyone had fork()ed, the "lock" preventing boundary-crossing was cleared. Then each areaserv began to dump out its huge chunk of memory-state into a file on an NFS server. Those files were then all tarred together and kept as a "backup" of the state of the server. These heavyweight backups happened at half-hour intervals, I believe."