Part 4: Datacenter Activation Coordination and the Prevention of Split Brainhttp://blogs.technet.com/b/timmcmic/archive/2013/02/03/part-4-datacenter-activation-coordination-and-the-prevention-of-split-brain.aspxIn Part 1 of this blog post series, I discussed the rules for mounting databases when Datacenter Activation Coordination (DAC) mode is enabled on a Database Availability Group (DAG).&#160; In this post, I want to look at the specific scenarios that applyen-USTelligent Evolution Platform Developer Build (Build: 5.6.50428.7875)re: Part 4: Datacenter Activation Coordination and the Prevention of Split Brainhttp://blogs.technet.com/b/timmcmic/archive/2013/02/03/part-4-datacenter-activation-coordination-and-the-prevention-of-split-brain.aspx#3561395Wed, 27 Mar 2013 17:50:22 GMTd5e57398-b9ef-4490-9955-07cbb4e4a80d:3561395exchposh<p>Hi Tim,</p> <p>Very nice series of articles, thanks for sharing, it helps me understand the DACP mode better now.</p> <p>I have a question with regards to this article.</p> <p>1. Imagine this scenario, there is a network outage between Site A and Site B</p> <p>2. Site A servers are all powered up (but not available to client network) or to Site B</p> <p>3. Business decides to Activate Site B</p> <p>4. We do all the required steps and now Site B is up and running (is it recommended to bring Site B up? )</p> <p>5. Now Site A Quorum will still be UP and DBs will be mounted</p> <p>6. Now if the network link between Site A and Site B comes back up</p> <p>7. What will happen?</p> <p>8. Is there any steps we can do to avoid this or does DACP mode already caters for this scenario?</p> <div style="clear:both;"></div><img src="http://blogs.technet.com/aggbug.aspx?PostID=3561395" width="1" height="1">re: Part 4: Datacenter Activation Coordination and the Prevention of Split Brainhttp://blogs.technet.com/b/timmcmic/archive/2013/02/03/part-4-datacenter-activation-coordination-and-the-prevention-of-split-brain.aspx#3551679Mon, 11 Feb 2013 14:50:40 GMTd5e57398-b9ef-4490-9955-07cbb4e4a80d:3551679TIMMCMIC<p>@Gangaiyan...</p> <p>No problem.</p> <p>TIMMCMIC</p> <div style="clear:both;"></div><img src="http://blogs.technet.com/aggbug.aspx?PostID=3551679" width="1" height="1">re: Part 4: Datacenter Activation Coordination and the Prevention of Split Brainhttp://blogs.technet.com/b/timmcmic/archive/2013/02/03/part-4-datacenter-activation-coordination-and-the-prevention-of-split-brain.aspx#3550927Wed, 06 Feb 2013 23:19:08 GMTd5e57398-b9ef-4490-9955-07cbb4e4a80d:3550927Harishpriyan<p>Thanks you very much for sharing it...</p> <div style="clear:both;"></div><img src="http://blogs.technet.com/aggbug.aspx?PostID=3550927" width="1" height="1">