I had a database set to high safety, synchronous mode without a mirror. The server containing the mirror went down, and caused the principle database to become read only. Every article I've read, it says that the mirror database becoming unavailable, should have no affect, except the principle database will run exposed. This is not the behavior I experienced. The principle database became read-only and no updates/inserts/deletes could take place.
High safety, synchronous mode means that a transaction needs to be committed on both the mirror and the principle. If the mirror becomes unavailable in the middle of a transaction, could it possibly cause an outage on the principle, since it wasn't committed on both?
Ideas?