I noticed D7 creates a field_revision table for every field, and duplicates the content from its field table counterpart even if one has revisions turned off.

I have a big text table and it is taking up a lot of space (several GBs).

Would it be safe to truncate the revision table?

PS: Meanwhile, I have also reported this as a bug.


Question: Local user accounts have disappeared after installing Active Directory and running dcpromo
Answer: When you install Active Directory, it removes any local accounts - this is well documented and intended functionality. As an aside, there are no primary and backup domain controllers any more - each DC is equal.

Reboot the machine - Active Directory should start back up again on reboot. If it doesn't, reboot again and keep tapping F8 and boot into Directory Services Restore Mode. You should then be able to log in and interrogate the Event Viewer for any clues why Active Directory isn't starting.