I would like to find out if it is possible to go straight from exchange 2013 cu 8/9 to exchange 2013 cu 14 or there are intermediate steps that should be followed?
Also what procedure should be followed for the upgrade.
We have 2 CAS servers behind a load balancer.
And 2 mailbox servers in a DAG.
Should I be upgrading 1 server, reboot that server and go to next server and so on
Specific procedure should be followed?
And what backups to take before the upgrade.
And what will be the restore procedure ?
Should I keep 1 Domain Controller shutdown during the upgrade and that way in case of issues just restore the exchange servers from backup and power on this DC(and shutdown others)?