Comments on: Database Availability Group (DAG) -Exchange 2010

By: Exchange Genie

Exchange Genie — Wed, 03 Mar 2010 18:15:41 +0000

Are you looking for information on the rcp arrays or just OWA etc… I have written an artile show CAS NLB for mapi connection with the new rpc client access array
http://www.exchange-genie.com/2009/09/momt-mapi-on-the-middle-teir/

By: it24by7

it24by7 — Tue, 02 Mar 2010 23:03:26 +0000

Genie,

This article is great but it would be great if you can post another article explaining the high availbility on the front end servers running the hub transport and the client access role.

Thanks!

By: Hayfe

Hayfe — Sat, 27 Feb 2010 09:03:23 +0000

I didn’t, but I will do it NOW
Great!

By: Exchange Genie

Exchange Genie — Fri, 26 Feb 2010 18:27:29 +0000

Did you read the artlce on rpc arrays for ex 2010 it talks about CAS load balances for mapi access and you can configure NLB for external users to make CAS server redundant

By: Hayfe

Hayfe — Fri, 26 Feb 2010 16:46:02 +0000

Great Article!
The next thing is: how to make the CAS Server HA…?
Great to have a DAG with eg. 3 or 4 MBX in it but the CAS Server ist a SPOF
Maby you have a good howto for that, too?

By: Exchange Genie

Exchange Genie — Fri, 19 Feb 2010 16:41:58 +0000

In Exchange 2010 the concept of single storage for HA is gone, there is no equivalent to SCC cluster. A DAG technology combines CCR clustering and SCR cluster from Exchange 2007 and uses replication.
You should use different storage connected to each mailbox server so that you have redundancy with hardware and storage.
When you setup a DAG there will be no disk resources in the cluster, ex 2010 only uses the heartbeat and cluster database of a Windows failover clustering.

By: Colby Trio

Colby Trio — Thu, 18 Feb 2010 23:53:54 +0000

We are about to move forward with Exchange 2010. We have done quite a bit of research regarding the Exchange 2007 to 2010 path but have not found an answer to some of our questions.

Our current Exchange 2007 configuration is as follows:

• 2 Exchange 2007 Mail Server servers
• Running in a SCC environment
• Servers connected via a Windows Cluster (cluser name: “email”)
• SAN is hosting the Exchange DB and Logs

***If more than one server accesses a database on a LUN it causes corruption. This means the new Exchange 2010 database cannot reside in the same LUN where there Exchange 2007 SCC database is stored***

We would like to move forward with the same layout for our Exchange 2010 environment using DAG. To minimize the impact to the Outlook users, we also need to keep the same cluster name (email) while we migrate the mailboxes.

Microsoft replied to this question with the following statement:
“According to the specialist, to have both using the same name, the SCC and DAG cannot be running at the same time. He recommended that the best option would be to rename the DAG, and plan accordingly around the name change.”

How should we proceed? I have looked through the Technet site and was not able to find any articles that would help.

Is there a way to perform this upgrade without effecting our Outlook 2007 users?

Thanks,
Colby

By: Matt Ashworth

Matt Ashworth — Fri, 29 Jan 2010 10:00:37 +0000

Great article, many thanks!

By: Exchange Genie

Exchange Genie — Tue, 05 Jan 2010 03:00:53 +0000

1. is the witness directory already created?
a.try creating the new directory
2. did you really put c:w or c:\w ?

Let me try to repro…

By: German Pulido

German Pulido — Mon, 04 Jan 2010 20:23:43 +0000

Hi!

I tried creating a DAG on a lab environment (2 exchange 2010 servers with CAS,hub and mailbox roles, and 1 Windows 2003 R2 DC) but despite adding \Exchange Trusted Subsystem\ to \BuiltinAdministrators\ and even adding domain controller’s computer account to \Exchange Trusted Subsystem\ (I know that shouldn’t be done, but I’m desperate here ) it fails to create the DAG. This is the error:

———————————————
Summary: 1 item(s). 0 succeeded, 1 failed.

Elapsed time: 00:00:01

DAG-01

Failed

Error:

Access is denied. (Exception from HRESULT: 0×80070005 (E_ACCESSDENIED))

Warning:

An unexpected error has occurred and a Watson dump is being generated: Access is denied. (Exception from HRESULT: 0×80070005 (E_ACCESSDENIED))

Exchange Management Shell command attempted:

New-DatabaseAvailabilityGroup -Name ‘DAG-01′ -WitnessServer ‘WIN2003DC’ -WitnessDirectory ‘c:w’

Elapsed Time: 00:00:01
———————————————

The command is run as the domain Administrator.

Any hint on this is appreciated.

Thanks!