I have exchange 2003. I will be migrating to exchange 2010 for the reason of high availibility. I have setup a test environment and need help with getting this high availibility option figured out.
I have 2 exchange server in my test environment Ex1 and Ex2 both running MB, CAS, & HUB role. I have a witness server regular w2k8 R2 server. I have set up a DAG for Ex1 & Ex2, replication is fine, in fact when one server goes down the other server mounts the databases.
I got the DAG part down, where i am having problems is getting my clients to remain connected when one server goes down. here is what i have tried and the issues i have faced:
1. Setting up CAS array for the 2 servers Ex1 & Ex2, that does not work coz windows NLB cannot coexist with clustering for DAG. Other resources i have read recommend using a third party device or software to do NLB, don't want that yet coz cost is an issue already.
2. Setting up witness server as the server clients connect to in outlook, it wont even let me do that it says the server cannot be found. i used the command below:
get-mailboxdatabase | set-mailboxdatabase -rpcclientaccessserver <FQDN of the array>
3. tried DNS round robin but it does not detect the state of the services for exchange so if server goes down it will continue sending traffic to the dead server.
I am trying to minimize my cost, i don't want to pay for any more exchange licenses, just want to use the the 2 that i have.
i don't want to buy new software or a new device to do the load balancing either.
Any input will be appreciated.