Exchange 2010 Site failover with two Stretched DAG

Hello Friends,

I am following the article : http://www.msexchange.org/articles-tutorials/exchange-server-2010/high-availability-recovery/designing-site-resilient-exchange-2010-solution-part3.html

In my Environment i have implemented two Mailbox server in Primary site and two in DR site, FSW is hosted by CASHT01 server in primary site and Alternate FSW in hosted in DR CASHT03 server. In my case what will happen if primary site gose down ? All DB will mount to DR autometically ? Will Alternate FSW will be act as voter node in case of primary FSW fail ? How the mejority and FSW will count if my primary site goes down?
LVL 3
binumicrosoftAsked:
Who is Participating?
 
DLeaverConnect With a Mentor Commented:
If the FSW is at the primary site then the same principle applies.

DAG's are not designed to work across multiple sites, so when you are dealing with stretched DAGS you need to understand that the site with the FSW will have the majority vote on the cluster.  If the primary site is lost then the server remaining only has a single vote on the quorum so in order for it to be brought up you will need to follow the instructions above.

In brief they;

- Remove the cluster
- Activate the Alternate FSW
- reestablish the cluster

You now have the 2 out of 3 vote on the quorum and the DAG can be started

*The underlying technology within an Exchange DAG is Windows Clustering service.   Therefore in order for the cluster to allow high availability there needs to be a majority vote on the quorum.

As you have two DAG's you have to consider where your FSW is as this will dictate the servers failover capabilities.
0
 
AmitIT ArchitectCommented:
Read Database Switch & Fail-Overs section given in the same link
0
 
DLeaverCommented:
That is a great article, I used it to setup a stretched DAG.

When you have a stretched DAG with the FSW at the primary site then if that site goes down you lose the majority share on the DAG and you have to manually intervene in order to bring the failover site up.

I used the below to create the .ps1 scripts needed for the manual switchover process to be made easy for my client - Henrik again of course...

http://www.msexchange.org/blogs/walther/news/real-life-exchange-2010-site-switchover-lesson-learned-637.html
0
Has Powershell sent you back into the Stone Age?

If managing Active Directory using Windows Powershell® is making you feel like you stepped back in time, you are not alone.  For nearly 20 years, AD admins around the world have used one tool for day-to-day AD management: Hyena. Discover why.

 
binumicrosoftAuthor Commented:
Hello Guys,

I have configured two mailbox node at each site and two DAG (DAG1 and DAG2). DAG 1 have two member server, one mailbox server of primary site and one mailbox server of secondary site. and the same is for DAG2 aswell. both are streatched DAG. eg. DAG1-mailbox server 1 database passive copy on secondary site - mailbox server 1 and the DAG 2 -mailbox server 2 database secondary site passive copy on primary site mailbox server2.

Can i achieve the automatic site failover? if not then what to do for that?
0
 
binumicrosoftAuthor Commented:
can we configure automatic site failover in exchange 2010, as per our  above setup? if not then how do i  automatic achieve site failover?
0
 
AmitIT ArchitectCommented:
Manual intervention is required. You need to have better monitoring in place, so you can act fast.
0
 
binumicrosoftAuthor Commented:
Thanks.
0
 
DLeaverCommented:
Just to be clear, if you hosted mailstores for your Company on the secondary site with passive copies on the primary site (where your FSW is located), then if the secondary site goes down then the passive copies will come up at the primary site - if the connection is lost to the second site and the second site Exchange is still up, the mailstores here will become unavailable with the error that connection to the FSW is lost - this prevents split brain.

If you are using this as just failover in the secondary site then when the primary site goes down, you lose all databases until the manual intervention steps are carried out as per my post above
0
 
binumicrosoftAuthor Commented:
I understand the failover scenario.

Thanks everyone!
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.