The meaning of ActivationPreference changed sometime in Exchange 2010, but I can’t remember what SP/UR. Before you do the Start-DatabaseAvailabilityGroup, you want to ensure that Site2 is preferred (because the servers in Site1 will not be “healthy” until they have caught up). Then reverse and *over when they are healthy.
Depending on how out of date the databases are, it may be just as fast (and certainly easier) to just remove the servers from the DAG, remove the database files, re-add the servers to the DAG and get a clean seed. Either should work fine. From: listsad...@lists.myitforum.com [mailto:listsad...@lists.myitforum.com] On Behalf Of Beahm, Keith Sent: Monday, November 14, 2016 4:01 PM To: exchange@lists.myitforum.com Subject: [Exchange] DAG operations after a datacenter power outage We run two DAGs each with an equal number of member servers* at each of two datacenters. Over the weekend we suffered an extended power outage at Site 1. After the Site 1 servers were shutdown we went thru the process of correcting a member server imbalance (i.e., there were more member servers at Site 1 in DAG1 than in Site 2). That was a careless oversight, but it was corrected by removing the 'extra' servers with Remove-DatabaseAvailabilityGroupServer -Identity DAG1 -MailboxServer ExchSvr1 –ConfigurationOnly. Once that completed we had to Stop the remote DAG servers in the down Site 1 using Stop-DatabaseAvailabilityGroup –Identity DAG1 -ActiveDirectorySite Site1 -ConfigurationOnly:$True. Then since we had already set the WitnessServer, and AlternateWitnessServer values with both Site values we ran Restore-DatabaseAvailabilityGroup -Identity DAG1 -ActiveDirectorySite Site2, and that allowed us to mount all the databases at Site 2. Fast forward to the restore of power at Site 1. We powered back on the exchange servers after a good delay for Site 1 DCs to complete replication of changes made at Site 2, and resumed all the mailbox database copies. All but two resumed without issue, but it was a 10 hour outage and mail flow was active the whole time. So my question to you is should I now run the Start-DatabaseAvailabilityGroup in the same way to bring these Site 1 servers back to an operational state (i.e., so they can participate in future failovers). Initially I didn’t detect that the DAGs were still reporting Stopped Mailbox Servers, so my 2nd question is will there be any impact to services when I run that command, assuming I am on the right track to begin with. The environment is Exchange 2010 SP2 RU4, and Server 2008 R2 SP1. Both DAGs have DatacenterActivationMode set to DagOnly. Thank you for your time and effort, any suggestions would be appreciated. And yes there is already a plan in place to apply SP3 RU14. Keith D. Beahm | Messaging and Storage Architect | Stinson Leonard Street LLP 1201 Walnut Street, Suite 2900 | Kansas City, MO 64106-2150 T: 816.691.3374 | M: 816.808.8983 | F: 816.412.1022 kbe...@stinson.com<mailto:kbe...@stinson.com> | www.stinson.com<http://www.stinson.com> This communication (including any attachments) is from a law firm and may contain confidential and/or privileged information. If it has been sent to you in error, please contact the sender for instructions concerning return or destruction, and do not use or disclose the contents to others.
