Dears,
i am having exchange 2007 installed on 4 servers , 2 mailbox and 2 hubcas servers and will migrate 2 exchange 2013 with highly available solution with 2 mailbox DAG and 2 cas servers in a network load balance.
i want to know if i could begin the migration with only one mailbox server and one cas server and later on add the other mailbox and other cas server