Comments on: Exchange 2010 RTM DAG using Server 2008 R2 – Part 4

By: EBE

EBE — Fri, 05 Mar 2010 16:25:01 +0000

Thx a lot for the sharing.
cu

By: Elan Shudnow

Elan Shudnow — Tue, 02 Mar 2010 00:25:37 +0000

No, don't use BPA to move DAG database/log file locations. Use the following guidance:
http://technet.microsoft.com/en-us/library/dd9797...

By: Tridon

Tridon — Mon, 01 Mar 2010 21:30:45 +0000

Another quick question:

We ran the Exchange Best practice analayzer, and it recommended to move a datastore from one drive to another drive where our log files are located. Our question comes in here, if we do this, do we also have to move it in the DAG or will the Best Practice Analayzer do it for us?

Thanks for the help in advance.

By: Elan Shudnow

Elan Shudnow — Sun, 28 Feb 2010 16:09:14 +0000

If you only have 2 servers for HA then ya, you'd need to have both servers being multi-role (CAS/HUB/Mailbox) as a Mailbox Server is useless without HUB and CAS. If you want your RPC Endpoint Highly Available as well (since RPC endpoint is now on CAS) you'll still need a hardware load balancer with only 2 servers as you cannot have Windows NLB and Windows Clustering Services on the same box.

So there's a couple options:
1. 2 Multi-Role DAG Serves with a hardware load balancer (or DNS Round Robin as a poor man's solution and removing 1 record when the server goes down and having a lowered TTL value for these records and understanding clients will lose affinity)
2. 4 Servers (2 MBX and 2 HUB/CAS) and use Windows NLB on the HUB/CAS which only uses Client IP Affinity (meaning if multiple users connect with the same IP 1 server can get more traffic)

By: Eric

Eric — Sat, 27 Feb 2010 19:12:43 +0000

We have a single 2010 server that was a "Typical" installation with the Hub Transport, Client Access, and Mailbox roles. We have all of our mailboxes on this server. We are ready to configure a 2nd server running 2008 Enterprise for failover purposes, and plan on configuring a DAG. When we install Exchange on the 2nd server, can it contain only the Mailbox role, or can it also be a "Typical" installation so that should the primary server fail, that mail flow still would route through this 2nd server? If not, when the primary server goes offline and only a Mailbox role exists on the 2nd server, what happens when a user tries to send internal and Internet mail? Is it routed and delivered, or que'd? I would presume it is que'd if only the Mailbox role exists?? Thanks for the excellent article above!

By: Andy

Andy — Fri, 26 Feb 2010 14:26:43 +0000

When assigning two addresses to the DAG, our failover cluster manager only shows one of the two addresses online, which means the "Whole" network name is not online. We can still ping the DAG though since it does have one ip online. Is that normal? Will the other address come online when a failover to that site occurs?

By: Elan Shudnow

Elan Shudnow — Fri, 26 Feb 2010 03:39:18 +0000

Yep, if you have CAS role on their own server, you can utilize Windows NLB. You can even use WNLB with a HUB/CAS Server.

By: eric

eric — Thu, 25 Feb 2010 20:39:01 +0000

Thanks for the informative article. If I have the CAS role on separate servers can I use NLB for them? Some articles state that you can not use NLB CAS servers if you are using the DAG. I believe that is true only if they are on the same server but that is never specifically stated.

By: Dinesh Silva

Dinesh Silva — Thu, 18 Feb 2010 16:28:53 +0000

really appreciate you postings. easy to understand and effective. looking forward to reaDd more articles here. :)

By: ROBERTO

ROBERTO — Mon, 15 Feb 2010 21:36:25 +0000

GRAZIE ELAN, E' UN TUTORIAL MOLTO UTILE
ROBERTO ROCCHETTI