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

By: baseliner35

baseliner35 — Thu, 25 Aug 2011 11:30:55 +0000

Hi,
I'm trying to investigate the cmdlet to remove my alternate FSW from my DAG. Cannot find anything about that and using the GUI doesn't seem to allow that

By: John Philipson

John Philipson — Tue, 02 Aug 2011 13:51:52 +0000

Fantastic Blog – One of the few on the Internet that was really clear, detailed and very helpful. I set up my environment with

all W2K8 R2 Standard (except for Mailbox servers running Enterprise Ed)

- DC
- CAS/HUB Server (as FSW) and
- 2x MAILBOX servers

The two node DAG works well, apart from a need to extend the timeouts to max, on the Cluster Failover (using the Exchange Shell script) to prevent the nodes dropping out of the cluster, for some mysterious reason, on my home LAB LAN.

By: Elan Shudnow

Elan Shudnow — Sun, 17 Apr 2011 22:25:57 +0000

Need to have 2 separate DAGs. Due to the way majority node clustering works, you can only have 1 site ever be up if you lose WAN connectivity due to majority of voters only being able to be in one site. If you require full connectivity for both sites, then you have to have 2 DAGs with DAG for SiteA having majority there and DAG for SiteB having majority there for the 2nd DAG.

By: Adrian

Adrian — Wed, 06 Apr 2011 10:31:59 +0000

Hi Elan, thanks for the great info.

I am looking at deploying a 2 node, 2 site DAG separated over a WAN. The config would be:

Site A: Server A with Active DB-A and Passive DB-B + FSW on a second server
Site B: Server B with Active DB-B and Passive DB-A

I have set this up and in initial testing the issue I have come across is that if the WAN link goes down, Server B looses access to the FSW and all databases in Site B are dismounted, meaning users who have mailboxes on Active DB-B are disconnected from Exchange and cannot use mail.

Is there a way to overcome this issue in a 2 node 2 site DAG, keeping in mind this is for a SMB with about 50 users who does want HA for email. I am doing this using Exchange SP1.

Thanks Adrian

By: Andrew

Andrew — Sun, 27 Feb 2011 03:48:44 +0000

Great write up… Very easy to follow and implement!

By: Dozer

Dozer — Fri, 31 Dec 2010 21:21:24 +0000

First, thanks for this write up !

For info in case anyone else comes across this:

Everything has worked fine so far, up until I tried to create the 'Add Mailbox Database Copy', I got a long error:
=================================================
Error:
=================================================
A source-side operation failed. Error An error occurred while performing the seed operation……..
Failed to open a log truncation context to source server 'server1.domain.local'. Hresult: 0xfffffae7. Error: The database was either not found or was not replicated.
=================================================

The fix I found here: http://smtp25.blogspot.com/2010/02/server-side-se…

…basically, manually copy across the 'CatalogData…' folders, then hit 'resume database copy', and all is well.

cheers

By: Lewinski

Lewinski — Fri, 24 Dec 2010 13:01:42 +0000

Elan, you know what, forget it – I'm an idiot :-)

It struck me as soon as I posted my comment that I didn't move the default admin mailbox to the DAG store… sorry!

By: Lewinski

Lewinski — Fri, 24 Dec 2010 12:38:47 +0000

Hi Elan,

Great article.

I created your setup on a virtual lab and went through everything as described. The exception is that I created two extra servers and put HT/CAS roles on both, and WNLB.

Accessing the CAS is fine, and the DAG does the fallover fine (Mounted, Healthy etc always seems in the right order).

However! unless EXC2 is switched on, I get mailbox unavailable errors. The setup works even if EXC2 is not the mounted copy, as long as the machine is on.

Any ideas would be greatly appreciated.

By: Farhan Raza

Farhan Raza — Tue, 23 Nov 2010 11:05:24 +0000

I am very thanks full.

By: Elan Shudnow

Elan Shudnow — Sat, 16 Oct 2010 13:52:39 +0000

You can have 2 DAG members in the Primary Site replicating all databases to a single node in the failover site. That'll work just fine.