If your databases contain text BLOBs storing non-ASCII data then the backup/restore cycle is not enough to upgrade them to ODS 11.1. Please pay attention to the files in the
/misc/upgrade/metadata directory of your Firebird 2.1 installation.
The configuration parameter
firebird.conf is now deprecated. You no longer need to disable it if you need to run multiple instances of Firebird simultaneously.
A long-standing, legacy loophole in the handling of DPB parameters enabled ordinary users to make connection settings that could lead to database corruptions or give them access to SYSDBA-only operations. This loophole has been closed, a change that could affect several existing applications, database tools and connectivity layers (drivers, components). Details are in Chapter 3 of the v.2.1.2 Release Notes, in Changes to the Firebird API and ODS.