66-update is a program that is normally used very rarely: when the 66 package is upgraded or downgraded, some services are currently managed, different tree as declared and the inner format has changed. This program transitions a complete tree and a live directory using a database with the old 66 format (the one being replaced) so that it uses a database with the new 66 format and rebuild the tree.
The point is to ensure a smooth transition between different versions of 66 without needing a reboot.
66-udpate [ -h ] [ -v verbosity ] [ -c ] [ -l live ] tree
If no tree is given, all trees of the owner of the process will be processed.
At the end of the process, the tree and the live state has not changed. Services already is use are not stopped or restarted during the transition process and match exactly the same state before and after the process.
It try to be safe as possible and exit 111 is a problem occurs. In any case on upgrade/downgrade time, 66 tools will not work properly if the transition is not made smoothly even by the sysadmin itself. So, We prefer to cratch instead of leaving an inconsistent state and let the sysadmin correct the things.