In the recent RSA Identity Governance and Lifecycle 7.0.1 Service Pack release we have added a feature to put the server in maintenance mode. This allows you to keep the server running while preventing any logins. When in this mode, no users are allowed to login to the system other than administrators. Other users are show a configurable login screen like the following:
In the meantime, administrators can login and do diagnosis or maintenance tasks.
Note: Active users are not kicked out of the system when you place the server into maintenance mode.