Thanks David, but my question was different:

If I need to add mirroring on a production system which at the time consists

of a single server (db01), do I have to block transactions before taking

the backup on (db01) and only allow them after the mirroring has been

setup?

Or the mirror server is able to apply any additional transactions that were issued

after the backup was taken on db01 and before the mirror was completely

setup (restore on db02 + mirror)

Thanks