Exchange 2013 DAG setup

I recently completed a migration from Exchange 2007 (with Windows 2008 SP2 OS - physical server) to Exchange 2013 (with Windows 2012 sp2 OS setup on ESX managed by vcenter and netapps FAS storage using ISCSI).
Also, I had another temporary Exchange 2013 (with Win 2012) server that was setup by previous IT admin and had 10 mailboxes migrated from 2007 and it was using different certificate and different CAS name. Now I have moved mailboxes from both server.
After decommissioning both the old exchange 2007 and 2013 I am planning to unjoin and join them back to domain. I was planning to use Windows 2008 r2 as witness server and Win 2012 with exchange 2013 as DAG member.
Is it possible to use Windows 2008 r2 as witness server with DAB members hosting Exchange 2013 in Win 2012 servers?
My single exchange server host both mailbox and front end role? Would it be possible to create DAG out of server hosting all server role? If so does secondary member only needs mail server role or all role as primary DAG member.
Is there a detail references of DAG setup? Both video and text blog would be appreciated.
pchettriIT DirectorAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Amit KumarCommented:
To create non-exchange server as file share witness please find below mentioned requirement:

There are three requirements we need to meet:

The Exchange Trusted Subsystem group in Active Directory must be added to the local Administrators group on the server that will be the file share witness
The File Server feature (FS-FileServer) must be installed on the file share witness
File and Print Sharing must be allowed through the Windows Firewall if the firewall is enabled

Ans for Ques:2 You can create DAG on multiple role installed Exchange server, but you will have to install same roles on secondary server as in case you don't have secondary server with CAS roles and primary server is down then you won't be able to access mailboxes.

One more thing, as you are installing Both roles on single server so CAS URLs will work on DNS round robin until you don't introduce Hardware load balancer or you can install CAS role on another server and configure then in NLB.

Please find this article as ref for Exchange DAG setup. This article will provide you best practice to configure DAG.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.