I have 2 site exchange 2010 on a DAG. Primary site A has all mailboxes replicated to site B. Site A exchange CAS role got corrupted with SP3 install so rolled back to sp2. Now all clients go to site B for CAS and then mailbox to site B. 100MB connection between site A & B.
I want to fix this issue. People are getting latency issue. I want to move exchange environment to 2013.
Question: Can I migrate exchange 2010 with SP2 (not SP3) directly to exchange 2013 or I should first install a healthy new exchange 2010 SP3 in DAG, move mailboxes and phase out the old one and then install a exchange 2013.