Hi DAG needs mail flow and replication flow. If communication network is ok, your solution is ok. Terence Yu TechNet Community Support

Note: Major edit done since original post! We are thinking we have the best alternative for migrating an Exchange 2010 server from one network/hardware/storage system to another, but we'd like a second opinion. First, here is the current configuration (simulated host names, in a higher Ed environment): primary.sub.domain.edu, primary Exchange 2010 server, with published OWA URL, MB, CAS and HUB roles, ActiveSync smartphones & other devices, use this server, firewall opening for SSL, currently in legacy network/hardware/storage secondary.sub.domain.edu, secondary Exchange 2010 server, with un-published OWA URL, no firewall opening, MB, CAS and HUB roles, DAG databases, in new network, has witness server in this network and has the new VM hardware/storage where we want to move the primary server, reflecting the desired final configuration. Both servers are Windows 2008 Enterprise, running on VMware as virtual machines. Both are listed as MX servers for our domain. We want to move the primary server into the same network as the secondary in the quickest time possible. The mailbox databases are large, 50-200 GB each, and moving the server as-is would take a very long time, even at 1 GB network speeds. So the approach we were considering is this: 1) Make secondary.sub.domain.edu the active mailbox database server for all databases. 2) Dismount the databases on the primary.sub.domain.edu server and change its IPs to the new network 3) Shut it down and then use the VMware tools to copy the machine associated with its C: drive to the new hardware/storage. 4) Next, create the storage for the databases and assign the drive letters to match the configuration of the drives when the primary server machine was shut down. 5) Copy the databases from the old hardware/storage to the new drives on the new storage hardware created in step 4. 6) Mount the databases and let the DAGs replicate to back fill all of the changes while the databases were offline. Is this the best approach or is there a better approach you can think of? SnoBoy

Hi Are you just changing the IP of the DAG member? Have you seen this thread: http://social.technet.microsoft.com/Forums/eu/exchange2010/thread/6cbaae34-aa77-4b2b-82c3-3dd21763339a Cheers, Steve

No, the VM for the primary Exchange server is moving from one physical server/storage to another in a completely different building. It unfortunately is nowhere as simple as that other scenario.SnoBoy

Hi DAG needs mail flow and replication flow. If communication network is ok, your solution is ok. Terence Yu TechNet Community Support

Let me give you an after-action report, because the DAG replication on large databases is always a pain to get going, which is the method we used to re-populate the databases on the server we moved. Every time (all 10 databases!) we created the DAG copy, it always ended in "Failed" or "Failed and Suspended." Having read many posts on these issues, I came upon a methodology that finally got all 10 databases synced. I think it was Einstein that said that insanity is doing the same thing over and over and expecting different results. However, doing the same thing over and over and getting different results in Computer Science, and that is what proved to be true in this exercise. Here is a write up of the process I did from my experiences and note that sometimes I went throught the 5 steps as many as 4 or 5 times before I got success! So, here is my write-up: Process for Adding a Database Copy (DAG) of an Existing Database Background We have had a lot of problems adding database copies of databases that are populated with mailboxes. It appears from my experience that the issue is a corrupt database search index, which consists of many files in a folder directly under the main database folder called CatalogData followed by a sting of alpha-numeric characters. The procedure below has worked every time to successfully get a working database copy in the DAG. Note: Never believe what shows in the Database Copies window unless you first click the Refresh button. In Organization Configuration, Mailbox, right-click the Database that you want to add a copy of and choose Add Mailbox Database Copy. The wizard starts and you need to choose the server that you want the copy on, my experience shows that the process will fail and that the copy will show Suspended or Failed and Suspended as the state.Next, stop the Microsoft Exchange Search Indexer on the destination server only.On the destination servers, find the directory where the Database you are working on is housed and delete the folder starting with Catalog.Next, restart the Microsoft Exchange Search Indexer service.Finally, right-click the database copy in the Suspended state and select Update Database Copy. Take the defaults in the wizard and let it work. It is a time consuming process and will take several minutes to hours, depending on database size. The Copy Status will show Seeding while the wizard is running. Sometimes you get to do the process over and over until magic happens and it finally succeeds. If the source server has a corrupt index (Catalog files), it may be necessary to stop the Indexing service on both servers, delete the Catalog directory files on both servers, restart the indexing service on both servers, then try Updating the copy. There is a fair likelihood that the first time wont work and may require the normal procedure above. SnoBoy