Thanks for a very good article.
On myth 10 - you cannot backup a mirrored database - I think you meant to say that the myth is that you can backup a mirrored database. The fact is that you cannot.
This changes in SQL 2012 though. If you use Always On Availability Groups a secondary replica can be backed up.
I wish this feature had been available in 2008 R2 as I needed to set up remote site backups for over 500 databases. I ended up log shipping all 500 databases to a remote site and used a bit of a hack to back them up. Though it's not officially supported it works. The process is..
- ensure the secondary database is in standby mode (i.e. readable)
- disable the restore job
- create a "dummy" database with the same # and types of files
- offline both databases
- copy the secondary database files over top of the dummy database files.
- bring both databases back online
- enable the restore job
- backup the "dummy" database
At this point you can backup the dummy database. If you want to be able to roll forward log backups, make sure you also save a copy of the corresponding undo file (*.tuf) with your backup.