When you want to use the Client Access Array function from exchange 2010. You have to options.
1. Use the NLB function in windows. Check this article that i blogged: Configuring NLB for Exchange 2010 for Cas load balancing.
2. When you have 2 physical load balancers in combination with a DAG cluster.
I haven't any pre-Created CAS arrays in my hyper-v.local domain. But you would to check of there is any pre-created CAS Arrays. Run the command below. if you didn't create a CAS Array before, you will get nothing .
Then you should create new Client Access Array. Run below Cmdlet in Exchange Management Console
New-ClientAccessArray –Name “CasArray1” –Fqdn casarray.hyper-v.local -Site “Default-First-Site-Name”
Now we have finished creating a CAS array. Then we must associate databases with this CAS Array.
Use below CMDLet to add mailbox database to CAS array. We can attach all mailbox databases at once as shown as shown below