Hi, we have to upgrade 2 Exchange 2013 CU3 Server to CU15 ( DAG activated ) they both run as virtual machines on different hyper-v servers.
what do we have to prepare to do this ?
how is the procedure ( Step by step )
and what should we do in advance if we run in a disaster ?
i learned that an CU installation will completely remove the exchange installation, what does that mean to the existing exchange settings ?
what does that mean to the mailboxes etc ?