I'm trying to figure out the best way to migrate a plesk installation from one server to another with the shortest possible downtime while ensuring source and destination server are consistent. I'll describe my current situation below, but I believe these questions are interesting to everybody wanting to migrate a plesk server. So this is my situation : - I've got a RH9 server with Plesk 7.5.3 - I need to upgrade it to RHEL 3.4 for several reasons (not in the least: bugfixes and recent packages) - I don't want to upgrade the OS on-the-fly, at least I haven't seen anybody recommending this. - I want to keep downtime very limited (much more than an hour downtime is unacceptable, even at night) So thought to migrate in three steps (spread over three nights): - migrate from production server to a temporary server; - reinstall production server with new software -migrate from temporary to production again. Problems: - A psadump takes about 2 hours: resulting in a 12GB zipped backup. - I tried restore: it took over 8 hours on a fast test machine. (restoring data takes 2 hours, checking and fixing another 6 hours !) - I need to shutdown FTP and Plesk Admin between start of backup and end of restore (over 10 hours). - I need to manually migrate databases again after restore because they have changed during those 10 hours - I need to migrate mail again for same reasons. - In the end it also seems a problem to simply swap machines as I want the IP address to be the same on both machines (I switch the cable so both machines are never online at the same time) because of router issues (different MAC address, same IP...) - If I change the IP, I need to change DNS entries which again causes problems of clients connecting to both machines at the same time (ns record ttl). ----- Thus, the question should be clear: what migration paths are other admins using, what tricks do you use to minimize downtime and maximize consistency between source and destination server ?