Hi!

> 1. Sometimes without any reasons if I send database to shutdown mode,
> it's not happened without killing all pro cesses of fb_inet_server.exe(I
> hope it's ok, because no one use database in this moment)

If the server can't set database in shutdown mode, it's still active in
working on the database. If you kill the server process in this case,
you can expect unwanted results.

You might try a tool like Sinatica or use monitoring tables, figure out
what's happening or to close all connections that are active at your
maintenace time.

Good look, Thomas