I've got three sites. Site1 has 1500 users (who's mailboxes are active in site2) and no Exchange servers, site2 will have a two-node DAG running on multi-role servers (no users), and site3 will have a stand-alone E2010 server without any active databases and 300 users (who's mailboxes are active in site2). I plan to take weekly full/daily incremental backups which can be restored to the server in site3. With this topology, if I lose site2, can I restore the backuped-up databases to site3, make them active, and point the CAS array's VIP to site3? If yes, what does the dns namespace in site3 look like - assuming webmail.company.com, mail.company.com, and autodiscover.company.com are used in site2? Thanks.

In theory that's possible, but it's not easy. I believe you'd need to dismount the database and take a backup of the file, though. I'm not sure your plan would work with an Exchange-aware backup unless you were to rename server 3 to the same name as where the backup was taken before restoring. Why don't you make server 3 a DAG member? Don't have the bandwidth? That would be much better than shipping tapes. You'd get better advice if you explained your business reasons for this plan. Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

I was thinking about cost. I'm trying to figure out how to get below budget. My goal is to build a topology with the fewest number of servers (with our previously described datacenter/user sites) that can tolerate any single failure (site, multi-role server, CAS service, HT service, or database). I've got a hardware load balancer at my disposal and redundant WAN links. So I suppose my question becomes more complicated. With these constraints, how should I lay out my environment? Would a two-server, two-DAG setup work (mbx/cas/ht at site2 and site3 with a witness in both sites)? I think that would cover a site outage for half the users and should also cover the database failure. Can we setup a CAS array that spans sites two and three? If yes, that would cover the CAS service failure. I saw an article that described receive connectors in a situation where the HT service was behind a hardware load balancer and that looked fine, but isn't there an Internet connector that sends mail out of the organization? If yes, where does that live and how do we plan to make it redundant? Hope that makes sense. Thanks.

1. I can't say with the limited information provided. Besides, I'm not going to do a design for you in a public forum. 2. You can't have a two-server two-DAG setup. Just one DAG. 3. You can but it probably doesn't make any sense. You really don't want a CAS serving users across a WAN connection. 4. It's called a send connector, and you have control over how it works. 5. It lives in AD. Transport servers follow its settings as it applies to them. Seriously, from the questions you're asking it's clear to me that you don't have enough background to be doing your own design. I strongly recommend that you pick up a good book and start reading.Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

Hi mhashemi, About the HA you could refer to below: http://technet.microsoft.com/en-us/library/dd638121.aspx About your plan, ED gave some good suggestion. Other tips for you, if you have hardware loadbalance, you could configure the CAS LB cross sites, you could turn to help from the HLB vendor. For the database in exchange 2010 scenario, it is supported to use on the other exchange 2010 mailbox server, but it is not convenient. That means if the exchange servers come back, the users mailbox already used the database on the mailbox in the site 3. The solution you referred just for restoring special mailbox or item sometimes, it is not recommended to use this method as the HA. I also think DAG/DAC is a better choice for you. Maybe need more server. Regards! Gavin

Hi mhashemi, About the HA you could refer to below: http://technet.microsoft.com/en-us/library/dd638121.aspx About your plan, ED gave some good suggestion. Other tips for you, if you have hardware loadbalance, you could configure the CAS LB cross sites, you could turn to help from the HLB vendor. For the database in exchange 2010 scenario, it is supported to use on the other exchange 2010 mailbox server, but it is not convenient. That means if the exchange servers come back, the users mailbox already used the database on the mailbox in the site 3. The solution you referred just for restoring special mailbox or item sometimes, it is not recommended to use this method as the HA. I also think DAG/DAC is a better choice for you. Maybe need more server. Regards! Gavin TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.