Redirect Outlook From Direct Server Connection To CAS Array

Microsoft has been always advice customer to configure CAS Array although there is only one server needed, unfortunately not many people is following this best practice.

My customer is going to deploy HA for their environment, which originally consist of 1 CAS/HUB server and 1 Mailbox server. Now they planning to have 1 more CAS/HUB server and mailbox server for HA purpose.

All the client is currently connected directly to the CAS and when  the new CAS is in place, I need to redirect them to connect to CAS Array.

There is around 700 users in the organization and I’m planning to perform the migration in a big bang strategy and minimize user’s downtime, so, I achieve the goal by using below steps:

  

1. Delete the old CAS DNS A record.

2. Create DNS A record for CAS Array.

3. Dismount all databases and re-mount them.

4. Outlook will perform a new autodiscover search and connect to CAS Array.

I hope this could help you to perform the migration with minimal user impact if you have a similar situation like this.