We are running a SQL 2005 database pair where we mirror two databases. I've created back-up jobs that check the mirror role and state of the mirror (from sys.database_mirroring) before running the back-up commands so we don't try to back-up a mirror database or the database when it's not in a synchronized state.

The back-up is written to a network share on the local network so no matter which of the two servers is the prinicpal, the back-up ends up in the same place.

Now I heard some concerns about breaking the log chain when there is a database fail-over. Is there anyone who can highlight the pitfalls we need to consider regarding our back-up and restore scheme in relation to the SQL 2005 mirroring. (Mirroring is synchronus)