When you’re operating an Exchange Server 2016 database availability group you’re going to eventually encounter a failed database copy. The most likely cause is a storage hardware issue, but there are many other ways that database copies can fail.
A failed database will show up in the output of Get-MailboxDatabaseCopyStatus, for example:
[PS] C:\>Get-MailboxDatabaseCopyStatus * | sort name Name Status CopyQueueLength ReplayQueueLength LastInspectedLogTime ContentIndexState ---- ------ --------------- ----------------- -------------------- ----------------- DB05\EX2016SRV1 Mounted 0 0 Healthy DB05\EX2016SRV2 Healthy 0 0 11/18/2015 10:45:39 PM Healthy DB06\EX2016SRV1 Healthy 0 0 11/18/2015 10:36:11 PM Healthy DB06\EX2016SRV2 Mounted 0 0 Healthy DB07\EX2016SRV1 Mounted 0 0 Healthy DB07\EX2016SRV2 Healthy 0 0 11/18/2015 10:46:44 PM Healthy DB08\EX2016SRV1 FailedAndSuspended 27 2 11/18/2015 4:50:59 PM Suspended DB08\EX2016SRV2 Mounted 0 0 Healthy
Recovery is a manual process if you are not using Autoreseed in your deployment. Once you’ve fixed the underlying issue (e.g. replaced the failed disk) you can reseed the database copy.
[PS] C:\>Suspend-MailboxDatabaseCopy DB08\EX2016SRV1 [PS] C:\>Update-MailboxDatabaseCopy DB08\EX2016SRV1
If the database and log paths on the server you’re reseeding to already contain files you can add the -DeleteExistingFiles switch to overwrite them.
[PS] C:\>Update-MailboxDatabaseCopy DB08\EX2016SRV1 -DeleteExistingFiles
Also, by default the source for the reseed will be the database copy that is currently active. If you’d prefer to reseed from a different server that may be closer, and therefore faster to reseed from, then you can add the -SourceServer parameter as well.
[PS] C:\>Update-MailboxDatabaseCopy DB08\EX2016SRV1 -SourceServer EX2016SRV2
The duration of the reseed operation will depend on the size of the database and transaction log data that needs to be copied across the network to the server.
After the reseed is complete the database copy should be back to a healthy state and will resume continuous replication.
This article Reseeding a Failed Database Copy in an Exchange Server 2016 Database Availability Group is © 2015 ExchangeServerPro.com
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