I've swapped DNS 35 days ago and I have seen that Google made long visit on the new server after 5 days and few short visits couple of days later and that’s it.
Since then I'm updating the two sites (with minor deferent so I could easily spot which site Google cached) and Google stubbornly keep visiting the old server (almost daily). Actually Google is one of the old server main visitors. Illustrating this weird situation is the big deference between the old server log file (1MB on September) and the new server log file (152MB on September).
I have to mention that it is the only site on the old server that Google keeps visit.
Is there anyone knowing how long I have to keep update both servers (and paid two hostess)?