Circular logging and adding new (second) database copy in Exchange 2013 DAG

Database “<DB_NAME>” has circular logging enabled. It is not possible to add or remove database copies while circular
logging is enabled. Please disable circular logging before adding or removing mailbox database copies. – this kind of error you might receive when trying to run command: Add-MailboxDatabaseCopy

Adding new (second) mailbox database copy in DAG enforces on us turning off JET circular logging on the database, of course we need to do it only when creating the first copy.

When you try to do it without it you might see below error:


Disabling DB copy can be made using command:

Set-MailboxDatabase wrodb02 -CircularLoggingEnabled $false

So after that we are getting below message with a reminder abut dismounting database:

circular_logging_2But let’s say what will happen if we won’t believe in that and we will try to add DB copy without re-mounting the database?

We may get:

The seeding operation failed. Error: An error occurred while performing the seed operation. Error: Failed to open a
log truncation context to source server ‘<SERVER_NAME>’. Hresult: 0xc7ff07db. Error: Failed to open a log
truncation context because ESE-level circular logging is enabled. Please dismount and then mount the database.

circular_logging_3Ok, so now I definitely see that this cannot be done this way, I knew that, but now we’ve tested it.

It ain’t that I don’t understand what they give in books.

circular_logging_9I just want to try what would happen! 😉

However, after re-mounting the DB, and trying to add DB copy we got another error though:

The database “WRODB02” already has a copy hosted on server “<SERVER_NAME>”. Choose a different server.


Weird, so it looks like the database is already mounted, checking that…and yeah, it is!:

circular_logging_5Ok! So let’s resume the database copy:


Hell yeah! So actually I was thinking that despite of warning it worked, no need to re-mount the database. Buuut.. my joy was not lasting long, after few minute I got “FailedAndSuspended” status. I thought that it was somehow fault of “ContentIndexState” was “Suspended”, but repairing that didn’t help:

circular_logging_7So..I ended up with full update of the database from the other server.

After the database is already in DAG, there is no need for dismounting it when switching On/Off from circular logging, that goes smoothly without need of re-mounting it:



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