lock the system and run a migration script. never do it manually bro.( make a backup only to replace if anything happened unplanned)
no!

can't lock the system brother, it must be run all the time and my updates must have installed while the live system is being run or we would loss bunch of valuable customers. The back up thing you've mentioned, yes that's what I thought and did.
I got a latest back up and installed my latest updates and then I compared current updated DB with the live DB and fulfilled the gaps. This is not easy! Perhaps I would switch the live DB to a empty temp. DB until my works are done.
I don't know, need a good way to fix this problem!
